- Email: [email protected]
Self-Reported Issues With Driving in Patients With Chronic Pain
Original Research
Self-Reported Issues With Driving in Patients With Chronic Pain Anita Fan, MD, FRCPC, Keith G. Wilson, PhD, Meena Acharya, MD, FRCPC, Anne Cranney, MD, FRCPC, Usha Buenger, MD, FRCPC, Shawn Marshall, MD, FRCPC Objective: To assess the driving habits, driving patterns, and barriers to driving reported by patients with chronic pain. Design: Cross-sectional mail survey with self-administered questionnaires. Setting: University-affiliated hospital. Participants: A sample of 223 patients seen in consultation by a physiatrist through the Chronic Pain Rehabilitation Service. Interventions: Not applicable. Main Outcome Measurements: Percentage of subjects who were current drivers, percentage of subjects experiencing difficulty with driving, and driving characteristics. Results: Response rate was 48.9%. Of the subjects, 79% were current drivers; of the nondrivers, 56% reported stopping driving because of chronic pain. A significantly greater percentage of nondrivers (80%) than drivers (62.9%) were women (P ⫽ .039). Nondrivers reported greater levels of pain than drivers (P ⫽ .027). The mean Pain Disability Index total score was significantly lower for drivers (42.3) than for nondrivers (48.7; P ⫽ .006). Of all subjects, 70% indicated that pain limited their driving in some manner; 41% of this group indicated that they experienced quite a bit or a great deal of difficulty driving. Factors that limited driving included pain (88.9%), fatigue (50.6%), limited joint mobility/stiffness (48.3%), and weakness (19.4%). The most frequently reported difficulties related to driving were sitting for any length of time (79.6%) and getting into the driver’s seat (66.5%). Only 2.4% of current drivers had been referred for a driving assessment. Conclusions: Most people with chronic pain continue to drive and overall appear to have better functioning than those who cannot continue driving because of chronic pain. Despite being able to drive, a significant proportion of drivers with chronic pain are facing challenges not only with driving the vehicle but also with entering and positioning themselves within the vehicle. Our results suggest that chronic pain does have an impact on driving. However, it appears to be generally unrecognized as a factor for driving other than when the implications of opioid use are considered. PM R 2012;4:87-95
INTRODUCTION Chronic pain is defined as “any continuous or persistent intermittent pain experienced for a period longer than three months” [1]. It is well established that chronic pain interferes with functional status, including personal mobility [2]; however, the effect that chronic pain and associated symptoms have on higher levels of mobility, such as driving, with implications for community access has not been well studied. The Canadian Medical Association Guidelines recommend that “patients who experience frequent, chronic and incapacitating pain should be advised to avoid driving while incapacitated” [3]. Unfortunately, these guidelines do not assist health care professionals or patients in the reality of day-to-day driving. Patients with stable symptoms and chronic pain do not have an increased safety risk, but in fact their symptoms are more likely to limit or curtail their ability to drive and therefore their independence and community access. PM&R 1934-1482/12/$36.00 Printed in U.S.A.
A.F. Department of Physical Medicine and Rehabilitation, The Ottawa Hospital Rehabilitation Centre, FRCPC, 408-1160 Burrard Street, Vancouver, BC, Canada, V6Z 2E8. Address correspondence to A.F.; e-mail: [email protected] Disclosure: nothing to disclose K.G.W. Department of Psychology, The Ottawa Hospital Rehabilitation Centre, Ottawa, Ontario, Canada Disclosure: nothing to disclose M.A. Department of Physical Medicine and Rehabilitation, The Ottawa Hospital Rehabilitation Centre, Ottawa, Ontario, Canada Disclosure: nothing to disclose A.C. Department of Rheumatology, Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada Disclosure: nothing to disclose U.B. Department of Physical Medicine and Rehabilitation, The Ottawa Hospital Rehabilitation Centre, Ottawa, Ontario, Canada Disclosure: nothing to disclose S.M. Department of Physical Medicine and Rehabilitation, The Ottawa Hospital Rehabilitation Centre, Ottawa, Ontario, Canada Disclosure: nothing to disclose Supported by AUTO21 through the Canadian Institutes of Health Research Team in Older Driver Research (Candrive). Peer reviewers and all others who control content have no relevant financial relationships to disclose. Disclosure Key can be found on the Table of Contents and at www.pmrjournal.org Submitted for publication March 17, 2011; accepted October 15, 2011.
© 2012 by the American Academy of Physical Medicine and Rehabilitation Vol. 4, 87-95, February 2012 DOI: 10.1016/j.pmrj.2011.10.008
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A comprehensive search of literature databases, including Ovid MEDLINE (1980-2010), CINAHL (1982-2010), and PsycINFO (2000-2010), was completed with the key words “driving” and “chronic pain.” Most studies identified in the literature search tended to focus on the effect of opioids on driving in the chronic pain population. In fact, the American Pain Society and the American Academy of Pain Medicine commissioned a systematic review of the evidence on long-term opioid therapy for chronic noncancer pain. The clinical guidelines recommend that clinicians counsel patients receiving long-term opioid therapy about transient or lasting cognitive impairment that may affect driving and work safety. The guidelines further advise that patients be counseled not to drive or engage in potentially dangerous activities when impaired or if they describe or demonstrate signs of impairment (strong recommendation, low-quality evidence) [4]. Although these safety recommendations are clearly important, the authors of most studies have shown that stable opioid use does not adversely affect patients’ driving performance [5-8] or cognitive and fine motor ability [9]. Patients with chronic pain who drove while taking opioid medications had no measurable impairments and demonstrated driving ability comparable to that of healthy subjects [10]. A structured evidence-based review indicated that opioids were not associated with intoxicated driving, motor vehicle accidents, or motor vehicle accident fatalities [11]. Similarly, in a study by Wingen et al [12] on medications for treatment of depression, they reported that driving performance and psychomotor functioning were not affected by these medications. Despite the fact that no study has been performed to examine the direct effect of chronic pain on driving ability, the authors of one study raised the hypothesis that both pain as well as pain-associated treatment could increase the risk of road traffic accidents [13] because each had the potential to affect physical or cognitive/psychomotor abilities. However, in a study in which the authors compared patients with chronic pain who were taking opioids, patients with chronic pain who were not taking opioids, and healthy volunteers, no significant differences among groups were found in measures of attention, reaction time, and driving errors [14]. In another study, the use of morphine improved the perceptual– cognitive status of patients with chronic nonmalignant pain despite its sedative side effects [15]. The authors concluded that pain itself, if not treated, had a negative impact on cognitive function. These findings were echoed in a study by Sjogren et al [16]. Most studies showed that intense pain significantly impaired cognitive performance [8,9,17-20]. Depression, pain-related anxiety, and insomnia, which were common symptoms experienced by patients with chronic pain, were significantly related to cognitive complaints such as memory problems and impaired function [21-24]. Therefore, it is logical to speculate that driving—a complex task that requires mental alertness; visual, auditory,
SELF-REPORTED ISSUES WITH DRIVING AND CHRONIC PAIN
and kinesthetic information processing; eye-hand coordination; and manual dexterity [25]—is affected by chronic pain. We identified only a few studies in which the authors evaluated the effect of chronic pain on specific driving limitations and the impact of chronic pain on individual driving patterns. One study revealed that individuals with low back pain (n ⫽ 16) had the most difficulty with use of the foot pedal, whereas 50% of those with fibromyalgia (n ⫽ 6) had difficulty with steering and cornering, reversing, and using the handbrake [26]. In a study involving older veterans, driving was identified as one of the instrumental activities of daily living affected by chronic pain [27]. Veldhuijzen et al [28] found that on an on-road driving test, the standard deviation of lateral car position was greater for patients with chronic nonmalignant pain than for matched healthy control patients, indicating worse highway driving performance. No information was revealed as to how chronic pain influences driving patterns, which may have significant implications for a population with already-limited personal mobility. By the identification of barriers to driving, interventions such as vehicle modifications or driving pattern strategies could potentially be developed to assist a population that continues to encounter daily barriers to independence. We performed a study to assess the driving habits and driving patterns of persons with chronic pain, and to explore the barriers to driving in these subjects. We hypothesized the following: (1) driving performance is affected by chronic pain; (2) persons with chronic pain have restricted driving patterns; and (3) restriction in driving in persons with chronic pain correlates with the amount of pain experienced.
METHODS The study was a cross-sectional mail survey of patients with chronic pain in which patients answered self-administered questionnaires. The study was approved by the Ottawa Hospital Rehabilitation Centre research ethics board.
Sample and Survey Procedure We created a list of 500 consecutive patients who were seen by a physiatrist in consultation through the Chronic Pain Rehabilitation Service (CPRS) at a hospital rehabilitation center as of November 1, 2006. This was a convenience sample of the first 500 cases during the time span (approximately 2 years). The CPRS is an outpatient program serving patients with chronic pain. Approximately 80% of the patients are fluent in both spoken and written English. A triage nurse reviews each referral to the CPRS, and diverts the referrals to the referral source or redirects them to other clinics if the patients referred do not fit the criteria for the chronic pain program (40% of referrals). The criteria include medical stability and demonstration of openness to a selfmanagement approach, emotional stability in group partici-
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pation, respect and sensitivity when interacting with others, willingness to increase functional independence, ability to participate in a group format, and commitment to attending the prescribed program. Therefore, patients who are seen by a physiatrist have already received the diagnosis of chronic pain from the referring physician and the triage nurse, and are deemed appropriate potential candidates for the CPRS. The sample size was determined by the use of a calculation for proportions in which it was estimated that 90% of this population would be active drivers [29]. For a desired confidence level of 90% and a confidence interval of 5%, we would require a minimum sample size of 97 respondents. We determined that we would need to sample 500 respondents. Approximately 20% of the population would be primarily French speaking and would not likely respond to an English language– based survey. We anticipated a response rate of 50%, but, given the time since visitation and the anonymous nature of the survey, we sent out 500 surveys to account for a response rate as low as 25%.
Inclusion Criteria Patients who had a primary diagnosis of chronic pain and were seen by a physiatrist in the CPRS were eligible for the study.
Survey Development We developed a questionnaire with the help of a multidisciplinary team composed of professionals from rheumatology, physiatry, psychology, nursing, and occupational therapy. Various aspects of driving patterns and pain characteristics of patients with chronic pain were identified in the survey. We achieved this by incorporating elements from the following surveys. The chronic pain intensity measures and the Patient Health Questionnaire have been demonstrated to be both valid and reliable [30,31]: ●
●
●
Driving Habits Questionnaire [32]: One component of this questionnaire (driving difficulty total score) pertains to driving difficulty under 8 different conditions (raining/ snowing, driving alone, parallel parking, making left-hand turns, driving on highways, driving on high-traffic highways, driving in rush-hour traffic, and driving at night). The ability to drive under these conditions is scored from 1 (most difficult) to 6 (least difficult). The final score is derived by adding the score for each of the 8 conditions (range of 6-48, with a higher score indicating less driving difficulty). Survey used by Cranney et al [33] to assess the driving difficulties and driving patterns encountered by patients with rheumatoid arthritis: We listed options/adaptations subjects might have in their vehicles and activities with which they might have difficulty before and during driving; the subjects checked the applicable ones. Pain intensity rated on a numerical rating scale from 0 (no pain) to 10 (as intense as you can imagine) [30].
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Summative pain score: The sum of numerical pain rating scale scores for current, worst, least, and average pain during the previous 2 weeks. This score is more stable (reliable) than the individual pain score items [30]. Pain Disability Index (PDI) [34]: This is a scale designed to measure the degree to which several aspects of the subject’s life are disrupted by chronic pain. For each of the 7 items (family/home responsibilities, recreation, social activity, occupation, sexual behavior, self-care, and life-support activity [activities necessary to sustain life, eg, breathing, maintaining blood pressure, ingesting food]), the patient rates the level of disability he/she experiences on a scale of 0 (no disability at all) to 10 (total disruption of all activities). The total PDI score is calculated by adding the PDI score for each of the 7 items (range of 0-70, with a higher score indicating higher disability). 9-Item Patient Health Questionnaire [31]: This is a screening instrument developed for depression. For each item, the patient indicates how much he/she has been bothered by the problem in the previous 2 weeks on a scale of 0 (not at all) to 3 (nearly every day). We included this instrument because patients with chronic pain are known to have an increased frequency of coexistent psychological distress, most notably depression and anxiety disorders [35]. It has also been shown that patients with chronic pain who have major depression have greater psychosocial disability than patients who are not depressed, and that they exhibit more cognitive distortion and activity limitation [36,37]. Therefore, depression is a confounding variable that could account for any poor driving ability and/or reduced quality of life detected.
We included a section for medications taken, grouped into analgesics, neuroleptics/antipsychotics, anti-inflammatory drugs, narcotics, antidepressants, antihistamines, benzodiazepines, muscle relaxants, intravenous analgesics, tricyclic antidepressants, and hypnotics.
Sample and Survey Method The survey was implemented according to Dillman’s Tailored Design Method [38] to maximize response rates. We obtained participants’ addresses from the hospital information systems. Mass mailings to all subjects were performed. A brief letter was sent to potential participants before the questionnaire mailing. The questionnaire was then sent, along with a cover letter explaining the purpose and significance of the study. Issues of confidentiality and voluntary participation were explained to the subject in this cover letter. As an incentive, a teabag was attached to the questionnaire for the respondent to enjoy while filling out the form. A reminder postcard was mailed 1 week after the initial mailing. A second questionnaire was sent to nonresponders 2 to 4 weeks after the first mailing. A stamped return envelope was included with both questionnaires. The estimated time to complete the questionnaire was 20 to 30 minutes.
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Table 1. Demographic characteristics of subjects with chronic pain by driving status Variable (No. of Valid Responses) Mean age (SD), years Females (215) Highest level of schooling completed (219) High school or less More than high school Current employment status (220) Employed/student (full-time or part-time) Unemployed Job requires driving (152) Marital status (217) Married or common-law Other Area of residence (213) Rural Urban
All Subjects N ⴝ 223
Drivers n ⴝ 176
Nondrivers n ⴝ 41
49.9 (10.4) 146 (66.4)
49.3 (10.1) 110 (62.9)
52.5 (11.9) 32 (80.0)
87 (39.7) 132 (60.3)
63 (36.2) 111 (63.8)
20 (50.0) 20 (50.0)
55 (25.0) 165 (75.0) 45 (29.6)
49 (28.0) 126 (72.0) 41 (32.8)
5 (12.5) 35 (87.5) 3 (12.5)
137 (63.1) 80 (36.9)
114 (66.3) 58 (33.7)
21 (52.5) 19 (47.5)
77 (36.2) 136 (63.8)
65 (38.5) 104 (61.5)
11 (28.2) 28 (71.8)
P Value .093* .039† .106†
.041†
.046† .103†
.217†
Values are n (%) or as indicated. Note: Driving status of 6 respondents was unknown. *Independent-samples t-test. † 2 test.
The questionnaires were coded only after they were returned to ensure respondent anonymity. A preaddressed postcard with the subject’s name was included with the questionnaire; subjects were asked to mail back the postcard so that we could identify those who had mailed in the questionnaire. Subjects mailed the postcard separately from the completed questionnaire, so it was not possible for any link to be made between individual respondents and their completed questionnaire. To further ensure anonymity, we shredded the returned postcards after identifying the respondents and nonrespondents.
Outcome Measures The outcome measures were as follows: (1) number of subjects currently driving who discontinued because of chronic pain or other reason; (2) number of subjects who had difficulty with driving because of their chronic pain or other reason; (3) the respondents’ driving habits and patterns (frequency of driving, dependence, difficulty, crashes, and citations); (4) data on specific driving problems encountered by patients with chronic pain (whether the subjects avoided driving because of chronic pain and the number and type of factors which made driving difficult); and (5) utility of driving resources (whether the subjects have been referred for a driver assessment and whether they were aware of programs or driver assessment centers).
Statistical Analysis Data entry, quality checks, and analyses were performed with SPSS v12.2 (SPSS Inc., Chicago, IL). The proportion of respondents selecting the various response options was cal-
culated for each question. Frequencies and cross-tabulations were calculated where applicable. Independent samples ttest and 2 tests were used for comparisons of continuous and dichotomous variables, respectively. We did not perform any corrections for multiple comparisons, given the exploratory nature of the study.
RESULTS Forty-four questionnaires were undeliverable, 41 because the address was incorrect or the subject had moved, and 3 because the subject had died. Of the remaining 456 questionnaires, 223 were returned completed, for a response rate of 48.9%.
Subject Characteristics The demographic characteristics of the subjects by driving status are presented in Table 1. The mean duration of chronic pain was 8 years 4 months. The average pain score over the previous 2 weeks was 6.2 (standard deviation [SD] 1.9). The mean PDI total score was 43.5 (SD 13.6; Table 2). There was no statistically significant difference between drivers and nondrivers in the total number of medications taken. The mean distance driven in an average week was 250.8 km (SD 478.6 km; 155.8 miles [SD 297.4 miles]). The mean driving difficulty score (under different conditions) in the previous month was 37.2 (SD 9.4). Approximately one-third of the subjects received advice about driving from their physician, occupational therapist, or physiotherapist. Only 2.4% had been referred for a driving assessment, and only 9% of the subjects were aware of driver assessment programs. A total of 5.9% reported having an accident in the previous year. Eleven accidents in the previ-
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Table 2. Pain characteristics and scores of pain, disability, and depression by driving status Variable
All Subjects
Drivers
Nondrivers
P Value
Pain duration, months Average pain over previous 2 weeks‡ Sum of pain scores (current ⫹ worst ⫹ least ⫹ average pain over previous 2 weeks) PDI total score§ PHQ-9 total score¶ Area of most pain Neck or back Other How current pain began Motor vehicle accident Other
99.7 (90.9) 6.2 (1.9) 25.6 (6.7)
94.3 (82.2) 6.1 (1.9) 25.0 (6.7)
118.3 (119.8) 6.6 (1.8) 27.7 (6.1)
.138* .118* .027*
43.5 (13.6) 13.9 (6.5)
42.3 (14.0) 13.6 (6.5)
48.7 (9.4) 15.8 (5.8)
.006* .080* .946†
111 (68.9) 50 (31.1)
84 (68.9) 38 (31.1)
25 (69.4) 11 (30.6)
51 (24.3) 159 (75.7)
42 (25.0) 126 (75.0)
9 (24.3) 28 (75.7)
.931†
Values are mean (standard deviation). PDI ⫽ Pain Disability Index; PHQ-9 ⫽ 9-item Patient Health Questionnaire. *Independent-samples t-test. † 2 test. ‡ Rated on a numerical rating scale from 0 (no pain) to 10 (as intense as you can imagine). § Each of 7 items was rated on a scale of 0 (no disability at all) to 10 (total disruption of all activities). ¶ Each of 9 items was rated on a scale of 0 (not at all) to 3 (nearly every day); lower scores indicate less depression.
ous year were reported (Table 3). From the questionnaire, a total of 45389.5 kilometers per week were driven by the subjects. This gives a total of 2.4 million kilometers driven per year. Therefore, the accident rate of 4.6 accidents per million kilometers (621,371.2 miles) driven was calculated.
analyzed, we found statistically significant differences between drivers and nondrivers in family/home responsibilities, recreation, social activity, occupation, and self-care (P ⱕ .010; Table 4).
Effect of Chronic Pain on Driving Differences Between Drivers and Nondrivers Of the 223 respondents, 176 were drivers and 41 were nondrivers. The driving status of 6 respondents was unknown (Table 1). Fifty-six percent of the nondrivers reported stopping driving because of their chronic pain; other reasons included cost (n ⫽ 3), not possessing a vehicle (n ⫽ 3), and fear (n ⫽ 2). A significantly greater proportion of nondrivers (80%) than drivers (62.9%) were women (P ⫽ .039). Nondrivers reported higher pain scores than drivers (P ⫽ .027; Table 2). The mean PDI total score was significantly lower for drivers (42.3) than for nondrivers (48.7; P ⫽ .006; Table 2). When the scores for the various items of the PDI were
Of all subjects, 70% indicated that their pain limited their driving in some manner; 41% of this group indicated that they experienced either quite a bit of difficulty or a great deal of difficulty driving. The factors that limited their driving included pain (88.9%), fatigue (50.6%), limited joint mobility/stiffness (48.3%), and weakness (19.4%). Only 6% reported having no difficulty at all. Subjects had difficulty with activities done both in preparation for (eg, adjusting mirrors) as well as during (eg, shoulder checks) driving. The problems encountered most frequently to prepare for driving were difficulty getting into the driver’s seat (66.5%), reaching for the seatbelt (47.6%), and opening and closing vehicle doors (37.3%; Table 5). Activities performed while driving that caused difficulty included sitting for any
Table 3. Characteristics of subjects regarding driving Variable (No. of Valid Responses) Received advice about driving from physician, occupational therapist, or physiotherapist (210) Referred for driving assessment (212) Aware of driving assessment programs (211) Had accident in previous year (186) Drives a car (177) Avoided driving in previous 6 months (176) Drives on divided highways (179) Drives on 2-lane highways (179) Has disabled parking permit (181)
No. (%) of Subjects 68 (32.4)
5 (2.4) 19 (9.0) 11 (5.9) 127 (71.8) 124 (70.4) 153 (85.5) 163 (91.1) 80 (44.2)
Table 4. Individual Pain Disability Index (PDI) scores for drivers vs nondrivers Item
Drivers
Nondrivers
P Value
Family/home responsibilities Recreation Social activity Occupation Sexual behavior Self-care Life-support activity
6.38 (2.08) 7.21 (2.14) 6.36 (2.49) 7.55 (2.40) 6.80 (2.69) 4.47 (2.60) 4.45 (3.02)
7.83 (1.58) 8.20 (1.55) 7.44 (1.76) 8.57 (1.32) 7.31 (2.91) 5.71 (2.55) 4.93 (2.88)
⬍.001* .006* .009* .010* .319* .007* .362*
Values are mean (SD). *Independent-samples t-test.
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Table 5. Activities related to driving that caused difficulty Activity (No. of Valid Responses) Sitting for any length of time (211) Getting into driver’s seat (212) Making shoulder checks (211) Reaching for seatbelt (212) Opening/closing vehicle doors (212) Reversing vehicle (211) Adjusting seat position (212) Fastening or unfastening seatbelt (212) Merging with traffic (211) Gripping steering wheel (211) Turning corners (211) Reaching to adjust mirrors (212) Controlling brake pedal or accelerator (211) Releasing handbrake (212) Steering (211) Shifting gears (210) Reaching to operate turn signals or controls on dashboard (211) Turning key/ignition (212)
No. (%) of Subjects 168 (79.6) 141 (66.5) 120 (56.9) 101 (47.6) 79 (37.3) 75 (35.5) 69 (32.5) 56 (26.4) 52 (24.6) 50 (23.7) 43 (20.4) 38 (17.9) 34 (16.1) 31 (14.6) 28 (13.3) 27 (12.9) 24 (11.4) 16 (7.5)
length of time (79.6%), making shoulder checks (56.9%), and merging with traffic (24.6%). The most common vehicle options used by subjects included automatic transmission, 4-door vehicles, and automatic windows (Table 6).
DISCUSSION The emphasis in the medical literature to date has been the study of the effect of chronic pain itself as well as treatments such as acute and chronic opioid therapy on driving safety. Although safety is clearly an important issue, the influence of chronic pain and its impact on driving patterns has not been studied. Multiple facets of driving, including frequency of driving, need for driving, the environmental conditions in which driving takes place, the distances driven, driving barriers, and vehicle adaptations, may all be influenced by the effects of chronic pain. The results of this cross-sectional survey indicate that chronic pain may play a role in both the ability or inability to drive as well as influencing driving patterns for those who do drive. This study is the first to examine differences between drivers and nondrivers who have chronic nonmalignant pain. A total of 79% of respondents with chronic nonmalignant pain drive. This rate is lower than the rate of driving in the general population, with 86% of Canadians holding a valid driver’s license and presumed to be driving [39,40]. The rate of driving in our study is greater than the rate of driving in individuals 65 and older. In this latter population, 75% have a valid driver’s license, and 60% drive a motor vehicle [41]. When we compared the demographics of drivers with nondrivers, we found that women with chronic pain are less likely to drive compared with men. However, for other factors such as age, level of education, marital status, and
urban versus rural living environment, there was no significant difference between these groups. Overall, nondrivers appear to be experiencing more pain on a day-to-day basis and, parallel to this, have more associated disability. Although pain alone would certainly be expected to affect multiple factors on the PDI score, it is certainly possible that limitations caused by an inability to drive could have a secondary influence on the items, including recreation, social, occupation, and even home responsibilities in which the independent use of a vehicle could play a significant role in performing these activities to their fullest. Interestingly, for activities potentially less dependent on the ability to drive, such as sexual behavior and life support activities, there was no significant difference between drivers and nondrivers on these items. Other factors, such as pain duration, depressive symptomatology, and pain location, did not vary significantly between groups, although there was a trend for mood to be lower among nondrivers. For those who do continue to drive, the 2 main issues that seem to be identified include (1) comfort and vehicle adjustments to maximize function, and (2) changes in driving patterns as a result of chronic pain. Most respondents indicated that they use car adaptations to help accommodate some of the pain that they are experiencing. Although the most common adaptations used were automatic transmission, 4-door vehicles, and automatic windows, these features often tend to be standard in vehicles in North America. However, some minor adaptations are clearly used to assist with pain limitations, such as seatbelt, gear stick, and pedal modifications, which each had a low frequency of use, similar to the findings of Cranney et al [33]. Despite the low use of these adaptations, a high proportion of drivers with chronic pain identify problems entering and positioning themselves within the vehicle where challenges are presented with opening and closing doors, getting into the driver seat, and even putting on their seatbelt. More Table 6. Frequency of use of car options and adaptations Option/Adaptation (N ⴝ 176) Automatic transmission 4-Door vehicle Automatic windows Additional back or seat support Power adjustable seat Remote starter Sliding doors Wide rear-view mirror or extra mirrors Padded/covered steering wheel 2-Door vehicle Other Key turners “Push-down” gear stick or lengthened gear stick Modified seatbelt mechanism Pedal modifications
No. (%) of Subjects 160 (90.9) 154 (87.5) 140 (79.5) 93 (52.8) 74 (42.0) 52 (29.5) 39 (17.0) 29 (16.5) 26 (14.8) 20 (11.4) 18 (10.2) 15 (8.5) 4 (2.3) 2 (1.1) 1 (0.6)
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concerning is the fact that driving actions themselves are adversely affected by pain and physical limitations in situtations in which drivers report limitations with actions such as sitting for any length of time, reversing the vehicle, performing shoulder checks, and merging with traffic. Although the significance of these findings is not completely clear because there is no direct control group, our study results yielded findings similar to those in the crosssectional survey by Cranney et al [33], in which 542 patients with rheumatoid arthritis were assessed. The respondents in this study indicated that the most limiting symptoms for driving were pain (57%) and stiffness (51.3%). Subjects further reported difficulty with activities performed both in preparation for and during driving. Similar to our study, the authors identified a high proportion of patients (40.2% vs 37.3% in our study) having difficulty with opening and closing doors. The percentage of patients having difficulty with reaching for the seatbelt in the Cranney et al study (38.1%) is also similar to that quoted in our study (47.6%). In our study, there was a much higher percentage of patients (66.5%) who had difficulty with getting into the driver’s seat, whereas this did not seem to affect the population as much (36.6%) in the Cranney et al study. This difference likely reflects the area of pain affected most in our study being the neck or back. Accordingly, in the study by Cranney et al [33], there was a much higher percentage of patients with difficulty turning the key/ignition (41.6%) compared with that found in our study (7.5%). This again reflects the disability in hand function specific to the rheumatoid arthritis population, which is not as prevalent in our population with chronic pain. Interestingly, 3 of the top 4 most difficult activities during driving are the same in our study and in the study by Cranney et al [33], ie, sitting for any length of time, making shoulder checks, and reversing the vehicle. The only activity in the top 4 most difficult activities during driving that differs in the 2 studies is gripping the wheel in the Cranney et al study [33] and merging with traffic in our study, which would require shoulder checking likely affected by neck and back discomfort. This finding again highlights the disability-specific problem with driving encountered in different populations. When compared with a sample of healthy older drivers (mean age 78 years) [42], drivers with chronic pain reported greater levels of difficulty with turning the steering wheel (13.3%) or depressing the gas pedal or brakes (16.1%) versus the difficulty encountered by older drivers (4.3% report of problem for each task). The percentage of elderly drivers having difficulty with shoulder checks when backing up was 28.7%, whereas the percentage of subjects in our study having difficulty with making shoulder checks is approximately twice as high at 56.9%. The higher percentages of patients having driving difficulties seen in the chronic pain population compared with the older, healthy drivers seem to indicate that chronic pain poses more challenges to driving than does advanced age. Therefore, these results imply that
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chronic pain should be considered similarly to other medical conditions, which are often known to be more prevalent with increasing age, when driving ability, comfort, and safety are assessed. Equal if not more research efforts need to be directed to how chronic pain affects driving. A total of 18.4% of our respondents were not driving currently, compared with 7.8% of the subjects in the survey by Cranney et al [33]. Almost 6% of our respondents reported an accident in the previous year. This percentage appears to be greater than the 8% in the previous 5 years reported by Cranney et al [33]. The collision rate data are not comparable because they are based on self-report, but they may indicate that persons with chronic pain do face more difficulties with driving. This has not been identified as a potential problem even in more recent reviews of chronic illnesses and impact on driving [43]. A control group of persons without chronic pain is not available for direct comparison of accident rates with the chronic pain patients group in our study. Two recent reviews do help to put crash records in perspective. In a comprehensive review by Charlton et al [44], the relative risks of crash for most medical conditions were summarized; however, chronic pain as a condition was not specifically identified. Charlton et al [44] did identify that relative risk for crash was slightly elevated (relative risk 1.1-2.0) for the category of drivers with physical impairments, which may most closely resemble drivers with chronic pain conditions. In a review, Marshall [45] also outlined the various relative risks of crash for different medical conditions but did not identify chronic pain as a specific condition. Although relative rates cannot be calculated, the accident rate derived from our study (4.6 accidents per million kilometers driven) can be assessed in light of the collision rate published by the Ontario Ministry of Transportation of 1.9 accidents per million kilometers travelled [46]. Our accident rate in chronic pain patients of 4.6 accidents per million kilometers driven is similar to the self-reported rate found in a sample of healthy older drivers [42], where the accident rate was observed to be 4.1 accidents per million kilometers driven. Although a direct comparison with a control group of subjects without chronic pain is not available in our study, drivers with chronic pain seem to have a moderately high crash risk compared with the general population and compared with individuals with some other medical conditions that are known to have an impact on function. Only 9% of our respondents were aware of driving assessment programs, compared with 15.5% of the patients in the survey by Cranney et al [33]. The lower proportion in our study may be attributable to the perception of health care professionals treating patients with chronic pain that their difficulties with driving do not warrant a formal assessment. Health care professionals may not see the need for patients with these difficulties to receive advice and counseling from the physician and/or therapist. Another possible
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explanation is that driving assessment programs are geared toward assessing functional driving ability after an acute event such as a stroke or spinal cord injury and are less focused on chronic disability, where the impairment is not as immediately evident. In the United States, there are educational programs such as CarFit, which is designed to help older drivers determine how well their vehicles “fit” them, to promote driver safety and community mobility (http://www.car-fit.org). Examples of areas addressed in this program include mirror adjustment and foot positioning on the gas and brake pedals. Such an educational program could be beneficial for patients with chronic pain, helping them to minimize disability and maximize safety. As in the study by Cranney et al [33], only a small proportion of our respondents (2.4%) were eventually referred for a driving assessment. Lack of referral to a driver assessment center may be attributable to costs associated with such centers. Another possible reason is that in Canada, physicians and patients alike probably do not regard chronic pain as having a major impact on driving. Disability from chronic pain is generally not regarded as a reportable condition by most physicians. In contrast, in Australia, an unconditional license is not issued if chronic pain is present that interferes with concentration or results in restriction/loss of joint movement that impairs driving. A conditional license may be issued only after a practical assessment [43]. When the effect of chronic pain on driving is not readily acknowledged, management or referrals to appropriate resources to help patients improve their driving ability, comfort, and accessibility will not take place. Potential study limitations include the self-reported nature of the data. Furthermore, our findings may not be generalizable to all persons with chronic pain because of the selection bias of choosing patients with chronic pain referred to a tertiary care rehabilitation center. Having a driver’s license at one point in the subject’s life was not an inclusion criterion. In addition, there may be biases, including selfselection, attributable to pain level or disability level and exclusion from the study attributable to language barrier. The fact that there is no information on the subjects who refused to participate in the survey could potentially affect the external validity of the study. The lack of a control group of subjects without chronic pain is another limitation. Establishing the relationship between chronic pain and driving patterns is an important first step in an attempt to improve the overall mobility and quality of life of chronic pain sufferers. The results of our study call for future research initiatives on controlled studies investigating the relationship between chronic pain and driving. This will in turn lead to studies in the future exploring interventions to make driving more accessible and comfortable for persons with chronic pain.
CONCLUSIONS Most people with chronic pain continue to drive and overall appear to have better functioning than those who cannot
SELF-REPORTED ISSUES WITH DRIVING AND CHRONIC PAIN
continue driving because of chronic pain. Despite being able to drive, a significant proportion of drivers with chronic pain are facing challenges not only with driving the vehicle but also with entering and positioning themselves within the vehicle. The implications with regards to safety and crash risk for those who have chronic pain remain unknown. Our results suggest that, not surprisingly, chronic pain does have an impact on driving. However, it appears to be generally unrecognized as a factor for driving other than when the implications of narcotic use are considered. Future research into the effect of chronic pain on driving, including the completion of controlled studies, is needed.
REFERENCES 1. Merskey H, Bogduk N. Classification of Chronic Pain. 2nd ed. Seattle: IASP Press; 1994. 2. Aronoff GM. Evaluation and Treatment of Chronic Pain. 3rd ed. Philadelphia: Lippincott Williams & Wilkins; 1999. 3. Determining Medical Fitness to Drive: A Guide for Physicians. 7th ed. Ottawa: Canadian Medical Association; 2006. 4. Chou, R, Fanciullo, GJ, Fine PG, et al. American Pain Society–American Academy of Pain Medicine Opioids Guidelines Panel. Clinical guidelines for the use of chronic opioid therapy in chronic noncancer pain. J Pain 2009;10:113-130. 5. Menefee LA, Frank ED, Crerand C, et al. The effects of transdermal fentanyl on driving, cognitive performance, and balance in patients with chronic nonmalignant pain conditions. Pain Med 2004;5:42-49. 6. Galski T, Williams JB, Ehle HT. Effects of opioids on driving ability. J Pain Symptom Manage 2000;19:200-208. 7. Kress HG, Kraft B. Opioid medication and driving ability. Eur J Pain 2005;9:141-144. 8. Vainio A, Ollila J, Matikainen E, Rosenberg P, Kalso E. Driving ability in cancer patients receiving long-term morphine analgesia. Lancet 1995; 346:667-670. 9. Jamison RN, Schein JR, Vallow S, Ascher S, Vorsanger GJ, Katz NP. Neuropsychological effects of long-term opioid use in chronic pain patients. J Pain Symptom Manage 2003;26:913-921. 10. Byas-Smith MG, Chapman SL, Reed B, Cotsonis G. The effect of opioids on driving and psychomotor performance in patients with chronic pain. Clin J Pain 2005;21:345-352. 11. Fishbain DA, Cutler RB, Rosomoff HL, Rosomoff RS. Can patients taking opioids drive safely? A structured evidence-based review. J Pain Palliat Care Pharmacother 2002;16:9-29. 12. Wingen M, Bothmer J, Langer S, Ramaekers JG. Actual driving performance and psychomotor function in healthy subjects after acute and subchronic treatment with escitalopram, mirtazapine, and placebo: A crossover trial. J Clin Psychiatry 2005;66:436-443. 13. Lagarde E, Chastang J, Lafont S, Coeuret-Pellicer M, Chiron M. Pain and pain treatment were associated with traffic accident involvement in a cohort of middle-aged workers. J Clin Epidemiol 2005;58:524-531. 14. Chapman SL, Byas-Smith MG, Reed BA. Effects of intermediate- and long-term use of opioids on cognition in patients with chronic pain. Clin J Pain 2002;18(Suppl):S83-S90. 15. Lorenz J, Beck H, Bromm B. Cognitive performance, mood and experimental pain before and during morphine-induced analgesia in patients with chronic non-malignant pain. Pain 1997;73:369-375. 16. Sjogren P, Thomsen AB, Olsen AK. Impaired neuropsychological performance in chronic nonmalignant pain patients receiving long-term oral opioid therapy. J Pain Symptom Manage 2000;19:100-108.
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17. Lorenz J, Bromm B. Event related potential correlates of interference between cognitive performance and tonic experimental pain. Psychophysiology 1997;34:436-445. 18. Crombez G, Eccleston C, Baeyens F, Eelen P. Habituation and the interference of pain with task performance. Pain 1997;70:149-154. 19. Crombez G, Eccleston C, Baeyens F, Eelen P. The disruptive nature of pain: An experimental investigation. Behav Res Ther 1996;34:911-918. 20. Sjogren P, Olsen AK, Thomsen AB, Dalberg J. Neuropsychological performance in cancer patients: The role of oral opioids, pain and performance status. Pain 2000;86:237-245. 21. McCracken LM, Iverson G. Predicting complaints of impaired cognitive functioning in patients with chronic pain. J Pain Symptom Manage 2001;21:392-396. 22. Munoz M, Esteve R. Reports of memory functioning by patients with chronic pain. Clin J Pain 2005;21:287-291. 23. Roth RS, Geisser ME, Theisen-Goodvich M, Dixon PJ. Cognitive complaints are associated with depression, fatigue, female sex, and pain catastrophizing in patients with chronic pain. Arch Phys Med Rehabil 2005;86:1147-1154. 24. Brown SC, Glass JM, Park DC. The relationship of pain and depression to cognitive function in rheumatoid arthritis patients. Pain 2002;96: 279-284. 25. Weiler JM, Bloomfield JR, Woodworth GG, et al. Effects of fexofenadine, diphenhydramine, and alcohol on driving performance. Ann Intern Med 2000;132:354-363. 26. Jones JG, McCann J, Lassere MN. Driving and arthritis. Br J Rheumatol 1991;30:361-364. 27. Duong BD, Kerns RD, Towle V, Reid MC. Identifying the activities affected by chronic nonmalignant pain in older veterans receiving primary care. J Am Geriatr Soc 2005;53:687-694. 28. Veldhuijzen DS, van Wijck AJM, Wille F, et al. Effect of chronic nonmalignant pain on highway driving performance. Pain 2006;122: 28-35. 29. Dimension Research Inc. Sample size for proportion calculator. 2005. Available at: http://www.dimensionresearch.com/resources/calculators/ sample_size.html. Accessed November 1, 2006. 30. Jensen MP, Turner JA, Romano JM, Fisher LD. Comparative reliability and validity of chronic pain intensity measures. Pain 1999;83: 157-162. 31. Kroenke K, Spitzer RL, Williams JB. The PHQ-9: Validity of a brief depression severity measure. J Gen Intern Med 2001;16:606-613. 32. Owsley C, Stalvey B, Wells J, Sloane ME. Older drivers and cataract: Driving habits and crash risk. J Gerontol A Biol Sci Med Sci 1999;54: M203-M211. 33. Cranney AB, Harrison A, Ruhland L et al. Driving problems in patients with rheumatoid arthritis. J Rheumatol 2005;32:2337-2342. 34. Jerome A, Gross RT. Pain Disability Index: Construct and discriminant validity. Arch Phys Med Rehabil 1991;72:920-922.
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35. Bennett RM, Burckhardt CS, Clark SR, O’Reilly CA, Wiens AN, Campbell SM. Group treatment of fibromyalgia: A 6 month outpatient program. J Rheumatol 1996;23:521-528. 36. Haley WE, Turner JA, Romano JM. Depression in chronic pain patients: Relation to pain, activity, and sex differences. Pain 1985;23:337-343. 37. Smith TW, O’Keeffe JL, Christensen AL. Cognitive distortion and depression in chronic pain: Association with diagnosed disorders. J Consult Clin Psychol 1994;62:195-198. 38. Dillman DA. Mail and Internet Surveys: The Tailored Design Method. 2nd ed. New York: Wiley; 2000. 39. Transport Canada. Number of licensed drivers by gender and age. 2006. Available at: http://www.tc.gc.ca/eng/roadsafety/tp-tp33222006-page11-594.htm. Accessed September 1, 2011. 40. Age and Sex Highlight Tables. 2006 Census. Statistics Canada Catalogue no. 97-551-XWE2006002. Ottawa, ON, Candada. Released July 17, 2007. 41. Statistics Canada, Canadian Community Health Survey—Healthy Aging, 2009. Available at: http://www.statcan.gc.ca/pub/16-002-x/16002-x2010004-eng.pdf. Accessed October 31, 2011. 42. Marshall SC, Molnar F, Man-Son-Hing M, Wilson KG, Stiell I. The Canadian Safe Driving Study—phase I pilot: Examining logistical barriers to the full cohort study. Paper presented at the International Conference on Aging, Disability and Independence, St. Petersburg, Florida, 2006, February. 43. Charlton J, Koppel S, O’Hare M, et al. Influence of chronic illness on crash involvement of motor vehicle drivers. Report No. 213. Clayton, Victoria, Australia: Monash University Accident Research Centre; 2004. 44. Charlton J, Koppel S, Odell M, et al. Influence of chronic illness on crash involvement of motor vehicle drivers. Report No. 300. Clayton, Victoria, Australia: Monash University Accident Research Centre; 2010. 45. Marshall SC. The role of reduced fitness to drive due to medical impairments in explaining crashes involving older drivers. Traffic Injury Prev 2008;9:291-298. 46. Ontario Ministry of Transportation. Ontario road safety annual report (ORSAR). 2007. Available at: http://www.mto.gov.on.ca/english/safety/ orsar/orsar07/collision.shtml. Accessed September 1, 2011. This CME activity is designated for 1.0 AMA PRA Category 1 Credit™ and can be completed online at me.aapmr.org. Log on to www.me.aapmr.org, go to Lifelong Learning (CME) and select Journal-based CME from the drop down menu. This activity is FREE to AAPM&R members and $25 for non-members.
CME Question Compared to people with chronic pain who continue to drive, those who stop driving: a. b. c. d.
have post high school education. are more likely to be female. have significantly shorter pain duration. have more likely been in an accident.
Answer online at me.aapmr.org
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Self-Reported Issues With Driving in Patients With Chronic Pain Anita Fan, MD, FRCPC, Keith G. Wilson, PhD, Meena Acharya, MD, FRCPC, Anne Cranney, MD, FRCPC, Usha Buenger, MD, FRCPC, Shawn Marshall, MD, FRCPC Objective: To assess the driving habits, driving patterns, and barriers to driving reported by patients with chronic pain. Design: Cross-sectional mail survey with self-administered questionnaires. Setting: University-affiliated hospital. Participants: A sample of 223 patients seen in consultation by a physiatrist through the Chronic Pain Rehabilitation Service. Interventions: Not applicable. Main Outcome Measurements: Percentage of subjects who were current drivers, percentage of subjects experiencing difficulty with driving, and driving characteristics. Results: Response rate was 48.9%. Of the subjects, 79% were current drivers; of the nondrivers, 56% reported stopping driving because of chronic pain. A significantly greater percentage of nondrivers (80%) than drivers (62.9%) were women (P ⫽ .039). Nondrivers reported greater levels of pain than drivers (P ⫽ .027). The mean Pain Disability Index total score was significantly lower for drivers (42.3) than for nondrivers (48.7; P ⫽ .006). Of all subjects, 70% indicated that pain limited their driving in some manner; 41% of this group indicated that they experienced quite a bit or a great deal of difficulty driving. Factors that limited driving included pain (88.9%), fatigue (50.6%), limited joint mobility/stiffness (48.3%), and weakness (19.4%). The most frequently reported difficulties related to driving were sitting for any length of time (79.6%) and getting into the driver’s seat (66.5%). Only 2.4% of current drivers had been referred for a driving assessment. Conclusions: Most people with chronic pain continue to drive and overall appear to have better functioning than those who cannot continue driving because of chronic pain. Despite being able to drive, a significant proportion of drivers with chronic pain are facing challenges not only with driving the vehicle but also with entering and positioning themselves within the vehicle. Our results suggest that chronic pain does have an impact on driving. However, it appears to be generally unrecognized as a factor for driving other than when the implications of opioid use are considered. PM R 2012;4:87-95
INTRODUCTION Chronic pain is defined as “any continuous or persistent intermittent pain experienced for a period longer than three months” [1]. It is well established that chronic pain interferes with functional status, including personal mobility [2]; however, the effect that chronic pain and associated symptoms have on higher levels of mobility, such as driving, with implications for community access has not been well studied. The Canadian Medical Association Guidelines recommend that “patients who experience frequent, chronic and incapacitating pain should be advised to avoid driving while incapacitated” [3]. Unfortunately, these guidelines do not assist health care professionals or patients in the reality of day-to-day driving. Patients with stable symptoms and chronic pain do not have an increased safety risk, but in fact their symptoms are more likely to limit or curtail their ability to drive and therefore their independence and community access. PM&R 1934-1482/12/$36.00 Printed in U.S.A.
A.F. Department of Physical Medicine and Rehabilitation, The Ottawa Hospital Rehabilitation Centre, FRCPC, 408-1160 Burrard Street, Vancouver, BC, Canada, V6Z 2E8. Address correspondence to A.F.; e-mail: [email protected] Disclosure: nothing to disclose K.G.W. Department of Psychology, The Ottawa Hospital Rehabilitation Centre, Ottawa, Ontario, Canada Disclosure: nothing to disclose M.A. Department of Physical Medicine and Rehabilitation, The Ottawa Hospital Rehabilitation Centre, Ottawa, Ontario, Canada Disclosure: nothing to disclose A.C. Department of Rheumatology, Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada Disclosure: nothing to disclose U.B. Department of Physical Medicine and Rehabilitation, The Ottawa Hospital Rehabilitation Centre, Ottawa, Ontario, Canada Disclosure: nothing to disclose S.M. Department of Physical Medicine and Rehabilitation, The Ottawa Hospital Rehabilitation Centre, Ottawa, Ontario, Canada Disclosure: nothing to disclose Supported by AUTO21 through the Canadian Institutes of Health Research Team in Older Driver Research (Candrive). Peer reviewers and all others who control content have no relevant financial relationships to disclose. Disclosure Key can be found on the Table of Contents and at www.pmrjournal.org Submitted for publication March 17, 2011; accepted October 15, 2011.
© 2012 by the American Academy of Physical Medicine and Rehabilitation Vol. 4, 87-95, February 2012 DOI: 10.1016/j.pmrj.2011.10.008
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A comprehensive search of literature databases, including Ovid MEDLINE (1980-2010), CINAHL (1982-2010), and PsycINFO (2000-2010), was completed with the key words “driving” and “chronic pain.” Most studies identified in the literature search tended to focus on the effect of opioids on driving in the chronic pain population. In fact, the American Pain Society and the American Academy of Pain Medicine commissioned a systematic review of the evidence on long-term opioid therapy for chronic noncancer pain. The clinical guidelines recommend that clinicians counsel patients receiving long-term opioid therapy about transient or lasting cognitive impairment that may affect driving and work safety. The guidelines further advise that patients be counseled not to drive or engage in potentially dangerous activities when impaired or if they describe or demonstrate signs of impairment (strong recommendation, low-quality evidence) [4]. Although these safety recommendations are clearly important, the authors of most studies have shown that stable opioid use does not adversely affect patients’ driving performance [5-8] or cognitive and fine motor ability [9]. Patients with chronic pain who drove while taking opioid medications had no measurable impairments and demonstrated driving ability comparable to that of healthy subjects [10]. A structured evidence-based review indicated that opioids were not associated with intoxicated driving, motor vehicle accidents, or motor vehicle accident fatalities [11]. Similarly, in a study by Wingen et al [12] on medications for treatment of depression, they reported that driving performance and psychomotor functioning were not affected by these medications. Despite the fact that no study has been performed to examine the direct effect of chronic pain on driving ability, the authors of one study raised the hypothesis that both pain as well as pain-associated treatment could increase the risk of road traffic accidents [13] because each had the potential to affect physical or cognitive/psychomotor abilities. However, in a study in which the authors compared patients with chronic pain who were taking opioids, patients with chronic pain who were not taking opioids, and healthy volunteers, no significant differences among groups were found in measures of attention, reaction time, and driving errors [14]. In another study, the use of morphine improved the perceptual– cognitive status of patients with chronic nonmalignant pain despite its sedative side effects [15]. The authors concluded that pain itself, if not treated, had a negative impact on cognitive function. These findings were echoed in a study by Sjogren et al [16]. Most studies showed that intense pain significantly impaired cognitive performance [8,9,17-20]. Depression, pain-related anxiety, and insomnia, which were common symptoms experienced by patients with chronic pain, were significantly related to cognitive complaints such as memory problems and impaired function [21-24]. Therefore, it is logical to speculate that driving—a complex task that requires mental alertness; visual, auditory,
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and kinesthetic information processing; eye-hand coordination; and manual dexterity [25]—is affected by chronic pain. We identified only a few studies in which the authors evaluated the effect of chronic pain on specific driving limitations and the impact of chronic pain on individual driving patterns. One study revealed that individuals with low back pain (n ⫽ 16) had the most difficulty with use of the foot pedal, whereas 50% of those with fibromyalgia (n ⫽ 6) had difficulty with steering and cornering, reversing, and using the handbrake [26]. In a study involving older veterans, driving was identified as one of the instrumental activities of daily living affected by chronic pain [27]. Veldhuijzen et al [28] found that on an on-road driving test, the standard deviation of lateral car position was greater for patients with chronic nonmalignant pain than for matched healthy control patients, indicating worse highway driving performance. No information was revealed as to how chronic pain influences driving patterns, which may have significant implications for a population with already-limited personal mobility. By the identification of barriers to driving, interventions such as vehicle modifications or driving pattern strategies could potentially be developed to assist a population that continues to encounter daily barriers to independence. We performed a study to assess the driving habits and driving patterns of persons with chronic pain, and to explore the barriers to driving in these subjects. We hypothesized the following: (1) driving performance is affected by chronic pain; (2) persons with chronic pain have restricted driving patterns; and (3) restriction in driving in persons with chronic pain correlates with the amount of pain experienced.
METHODS The study was a cross-sectional mail survey of patients with chronic pain in which patients answered self-administered questionnaires. The study was approved by the Ottawa Hospital Rehabilitation Centre research ethics board.
Sample and Survey Procedure We created a list of 500 consecutive patients who were seen by a physiatrist in consultation through the Chronic Pain Rehabilitation Service (CPRS) at a hospital rehabilitation center as of November 1, 2006. This was a convenience sample of the first 500 cases during the time span (approximately 2 years). The CPRS is an outpatient program serving patients with chronic pain. Approximately 80% of the patients are fluent in both spoken and written English. A triage nurse reviews each referral to the CPRS, and diverts the referrals to the referral source or redirects them to other clinics if the patients referred do not fit the criteria for the chronic pain program (40% of referrals). The criteria include medical stability and demonstration of openness to a selfmanagement approach, emotional stability in group partici-
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pation, respect and sensitivity when interacting with others, willingness to increase functional independence, ability to participate in a group format, and commitment to attending the prescribed program. Therefore, patients who are seen by a physiatrist have already received the diagnosis of chronic pain from the referring physician and the triage nurse, and are deemed appropriate potential candidates for the CPRS. The sample size was determined by the use of a calculation for proportions in which it was estimated that 90% of this population would be active drivers [29]. For a desired confidence level of 90% and a confidence interval of 5%, we would require a minimum sample size of 97 respondents. We determined that we would need to sample 500 respondents. Approximately 20% of the population would be primarily French speaking and would not likely respond to an English language– based survey. We anticipated a response rate of 50%, but, given the time since visitation and the anonymous nature of the survey, we sent out 500 surveys to account for a response rate as low as 25%.
Inclusion Criteria Patients who had a primary diagnosis of chronic pain and were seen by a physiatrist in the CPRS were eligible for the study.
Survey Development We developed a questionnaire with the help of a multidisciplinary team composed of professionals from rheumatology, physiatry, psychology, nursing, and occupational therapy. Various aspects of driving patterns and pain characteristics of patients with chronic pain were identified in the survey. We achieved this by incorporating elements from the following surveys. The chronic pain intensity measures and the Patient Health Questionnaire have been demonstrated to be both valid and reliable [30,31]: ●
●
●
Driving Habits Questionnaire [32]: One component of this questionnaire (driving difficulty total score) pertains to driving difficulty under 8 different conditions (raining/ snowing, driving alone, parallel parking, making left-hand turns, driving on highways, driving on high-traffic highways, driving in rush-hour traffic, and driving at night). The ability to drive under these conditions is scored from 1 (most difficult) to 6 (least difficult). The final score is derived by adding the score for each of the 8 conditions (range of 6-48, with a higher score indicating less driving difficulty). Survey used by Cranney et al [33] to assess the driving difficulties and driving patterns encountered by patients with rheumatoid arthritis: We listed options/adaptations subjects might have in their vehicles and activities with which they might have difficulty before and during driving; the subjects checked the applicable ones. Pain intensity rated on a numerical rating scale from 0 (no pain) to 10 (as intense as you can imagine) [30].
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Summative pain score: The sum of numerical pain rating scale scores for current, worst, least, and average pain during the previous 2 weeks. This score is more stable (reliable) than the individual pain score items [30]. Pain Disability Index (PDI) [34]: This is a scale designed to measure the degree to which several aspects of the subject’s life are disrupted by chronic pain. For each of the 7 items (family/home responsibilities, recreation, social activity, occupation, sexual behavior, self-care, and life-support activity [activities necessary to sustain life, eg, breathing, maintaining blood pressure, ingesting food]), the patient rates the level of disability he/she experiences on a scale of 0 (no disability at all) to 10 (total disruption of all activities). The total PDI score is calculated by adding the PDI score for each of the 7 items (range of 0-70, with a higher score indicating higher disability). 9-Item Patient Health Questionnaire [31]: This is a screening instrument developed for depression. For each item, the patient indicates how much he/she has been bothered by the problem in the previous 2 weeks on a scale of 0 (not at all) to 3 (nearly every day). We included this instrument because patients with chronic pain are known to have an increased frequency of coexistent psychological distress, most notably depression and anxiety disorders [35]. It has also been shown that patients with chronic pain who have major depression have greater psychosocial disability than patients who are not depressed, and that they exhibit more cognitive distortion and activity limitation [36,37]. Therefore, depression is a confounding variable that could account for any poor driving ability and/or reduced quality of life detected.
We included a section for medications taken, grouped into analgesics, neuroleptics/antipsychotics, anti-inflammatory drugs, narcotics, antidepressants, antihistamines, benzodiazepines, muscle relaxants, intravenous analgesics, tricyclic antidepressants, and hypnotics.
Sample and Survey Method The survey was implemented according to Dillman’s Tailored Design Method [38] to maximize response rates. We obtained participants’ addresses from the hospital information systems. Mass mailings to all subjects were performed. A brief letter was sent to potential participants before the questionnaire mailing. The questionnaire was then sent, along with a cover letter explaining the purpose and significance of the study. Issues of confidentiality and voluntary participation were explained to the subject in this cover letter. As an incentive, a teabag was attached to the questionnaire for the respondent to enjoy while filling out the form. A reminder postcard was mailed 1 week after the initial mailing. A second questionnaire was sent to nonresponders 2 to 4 weeks after the first mailing. A stamped return envelope was included with both questionnaires. The estimated time to complete the questionnaire was 20 to 30 minutes.
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Table 1. Demographic characteristics of subjects with chronic pain by driving status Variable (No. of Valid Responses) Mean age (SD), years Females (215) Highest level of schooling completed (219) High school or less More than high school Current employment status (220) Employed/student (full-time or part-time) Unemployed Job requires driving (152) Marital status (217) Married or common-law Other Area of residence (213) Rural Urban
All Subjects N ⴝ 223
Drivers n ⴝ 176
Nondrivers n ⴝ 41
49.9 (10.4) 146 (66.4)
49.3 (10.1) 110 (62.9)
52.5 (11.9) 32 (80.0)
87 (39.7) 132 (60.3)
63 (36.2) 111 (63.8)
20 (50.0) 20 (50.0)
55 (25.0) 165 (75.0) 45 (29.6)
49 (28.0) 126 (72.0) 41 (32.8)
5 (12.5) 35 (87.5) 3 (12.5)
137 (63.1) 80 (36.9)
114 (66.3) 58 (33.7)
21 (52.5) 19 (47.5)
77 (36.2) 136 (63.8)
65 (38.5) 104 (61.5)
11 (28.2) 28 (71.8)
P Value .093* .039† .106†
.041†
.046† .103†
.217†
Values are n (%) or as indicated. Note: Driving status of 6 respondents was unknown. *Independent-samples t-test. † 2 test.
The questionnaires were coded only after they were returned to ensure respondent anonymity. A preaddressed postcard with the subject’s name was included with the questionnaire; subjects were asked to mail back the postcard so that we could identify those who had mailed in the questionnaire. Subjects mailed the postcard separately from the completed questionnaire, so it was not possible for any link to be made between individual respondents and their completed questionnaire. To further ensure anonymity, we shredded the returned postcards after identifying the respondents and nonrespondents.
Outcome Measures The outcome measures were as follows: (1) number of subjects currently driving who discontinued because of chronic pain or other reason; (2) number of subjects who had difficulty with driving because of their chronic pain or other reason; (3) the respondents’ driving habits and patterns (frequency of driving, dependence, difficulty, crashes, and citations); (4) data on specific driving problems encountered by patients with chronic pain (whether the subjects avoided driving because of chronic pain and the number and type of factors which made driving difficult); and (5) utility of driving resources (whether the subjects have been referred for a driver assessment and whether they were aware of programs or driver assessment centers).
Statistical Analysis Data entry, quality checks, and analyses were performed with SPSS v12.2 (SPSS Inc., Chicago, IL). The proportion of respondents selecting the various response options was cal-
culated for each question. Frequencies and cross-tabulations were calculated where applicable. Independent samples ttest and 2 tests were used for comparisons of continuous and dichotomous variables, respectively. We did not perform any corrections for multiple comparisons, given the exploratory nature of the study.
RESULTS Forty-four questionnaires were undeliverable, 41 because the address was incorrect or the subject had moved, and 3 because the subject had died. Of the remaining 456 questionnaires, 223 were returned completed, for a response rate of 48.9%.
Subject Characteristics The demographic characteristics of the subjects by driving status are presented in Table 1. The mean duration of chronic pain was 8 years 4 months. The average pain score over the previous 2 weeks was 6.2 (standard deviation [SD] 1.9). The mean PDI total score was 43.5 (SD 13.6; Table 2). There was no statistically significant difference between drivers and nondrivers in the total number of medications taken. The mean distance driven in an average week was 250.8 km (SD 478.6 km; 155.8 miles [SD 297.4 miles]). The mean driving difficulty score (under different conditions) in the previous month was 37.2 (SD 9.4). Approximately one-third of the subjects received advice about driving from their physician, occupational therapist, or physiotherapist. Only 2.4% had been referred for a driving assessment, and only 9% of the subjects were aware of driver assessment programs. A total of 5.9% reported having an accident in the previous year. Eleven accidents in the previ-
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Table 2. Pain characteristics and scores of pain, disability, and depression by driving status Variable
All Subjects
Drivers
Nondrivers
P Value
Pain duration, months Average pain over previous 2 weeks‡ Sum of pain scores (current ⫹ worst ⫹ least ⫹ average pain over previous 2 weeks) PDI total score§ PHQ-9 total score¶ Area of most pain Neck or back Other How current pain began Motor vehicle accident Other
99.7 (90.9) 6.2 (1.9) 25.6 (6.7)
94.3 (82.2) 6.1 (1.9) 25.0 (6.7)
118.3 (119.8) 6.6 (1.8) 27.7 (6.1)
.138* .118* .027*
43.5 (13.6) 13.9 (6.5)
42.3 (14.0) 13.6 (6.5)
48.7 (9.4) 15.8 (5.8)
.006* .080* .946†
111 (68.9) 50 (31.1)
84 (68.9) 38 (31.1)
25 (69.4) 11 (30.6)
51 (24.3) 159 (75.7)
42 (25.0) 126 (75.0)
9 (24.3) 28 (75.7)
.931†
Values are mean (standard deviation). PDI ⫽ Pain Disability Index; PHQ-9 ⫽ 9-item Patient Health Questionnaire. *Independent-samples t-test. † 2 test. ‡ Rated on a numerical rating scale from 0 (no pain) to 10 (as intense as you can imagine). § Each of 7 items was rated on a scale of 0 (no disability at all) to 10 (total disruption of all activities). ¶ Each of 9 items was rated on a scale of 0 (not at all) to 3 (nearly every day); lower scores indicate less depression.
ous year were reported (Table 3). From the questionnaire, a total of 45389.5 kilometers per week were driven by the subjects. This gives a total of 2.4 million kilometers driven per year. Therefore, the accident rate of 4.6 accidents per million kilometers (621,371.2 miles) driven was calculated.
analyzed, we found statistically significant differences between drivers and nondrivers in family/home responsibilities, recreation, social activity, occupation, and self-care (P ⱕ .010; Table 4).
Effect of Chronic Pain on Driving Differences Between Drivers and Nondrivers Of the 223 respondents, 176 were drivers and 41 were nondrivers. The driving status of 6 respondents was unknown (Table 1). Fifty-six percent of the nondrivers reported stopping driving because of their chronic pain; other reasons included cost (n ⫽ 3), not possessing a vehicle (n ⫽ 3), and fear (n ⫽ 2). A significantly greater proportion of nondrivers (80%) than drivers (62.9%) were women (P ⫽ .039). Nondrivers reported higher pain scores than drivers (P ⫽ .027; Table 2). The mean PDI total score was significantly lower for drivers (42.3) than for nondrivers (48.7; P ⫽ .006; Table 2). When the scores for the various items of the PDI were
Of all subjects, 70% indicated that their pain limited their driving in some manner; 41% of this group indicated that they experienced either quite a bit of difficulty or a great deal of difficulty driving. The factors that limited their driving included pain (88.9%), fatigue (50.6%), limited joint mobility/stiffness (48.3%), and weakness (19.4%). Only 6% reported having no difficulty at all. Subjects had difficulty with activities done both in preparation for (eg, adjusting mirrors) as well as during (eg, shoulder checks) driving. The problems encountered most frequently to prepare for driving were difficulty getting into the driver’s seat (66.5%), reaching for the seatbelt (47.6%), and opening and closing vehicle doors (37.3%; Table 5). Activities performed while driving that caused difficulty included sitting for any
Table 3. Characteristics of subjects regarding driving Variable (No. of Valid Responses) Received advice about driving from physician, occupational therapist, or physiotherapist (210) Referred for driving assessment (212) Aware of driving assessment programs (211) Had accident in previous year (186) Drives a car (177) Avoided driving in previous 6 months (176) Drives on divided highways (179) Drives on 2-lane highways (179) Has disabled parking permit (181)
No. (%) of Subjects 68 (32.4)
5 (2.4) 19 (9.0) 11 (5.9) 127 (71.8) 124 (70.4) 153 (85.5) 163 (91.1) 80 (44.2)
Table 4. Individual Pain Disability Index (PDI) scores for drivers vs nondrivers Item
Drivers
Nondrivers
P Value
Family/home responsibilities Recreation Social activity Occupation Sexual behavior Self-care Life-support activity
6.38 (2.08) 7.21 (2.14) 6.36 (2.49) 7.55 (2.40) 6.80 (2.69) 4.47 (2.60) 4.45 (3.02)
7.83 (1.58) 8.20 (1.55) 7.44 (1.76) 8.57 (1.32) 7.31 (2.91) 5.71 (2.55) 4.93 (2.88)
⬍.001* .006* .009* .010* .319* .007* .362*
Values are mean (SD). *Independent-samples t-test.
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Table 5. Activities related to driving that caused difficulty Activity (No. of Valid Responses) Sitting for any length of time (211) Getting into driver’s seat (212) Making shoulder checks (211) Reaching for seatbelt (212) Opening/closing vehicle doors (212) Reversing vehicle (211) Adjusting seat position (212) Fastening or unfastening seatbelt (212) Merging with traffic (211) Gripping steering wheel (211) Turning corners (211) Reaching to adjust mirrors (212) Controlling brake pedal or accelerator (211) Releasing handbrake (212) Steering (211) Shifting gears (210) Reaching to operate turn signals or controls on dashboard (211) Turning key/ignition (212)
No. (%) of Subjects 168 (79.6) 141 (66.5) 120 (56.9) 101 (47.6) 79 (37.3) 75 (35.5) 69 (32.5) 56 (26.4) 52 (24.6) 50 (23.7) 43 (20.4) 38 (17.9) 34 (16.1) 31 (14.6) 28 (13.3) 27 (12.9) 24 (11.4) 16 (7.5)
length of time (79.6%), making shoulder checks (56.9%), and merging with traffic (24.6%). The most common vehicle options used by subjects included automatic transmission, 4-door vehicles, and automatic windows (Table 6).
DISCUSSION The emphasis in the medical literature to date has been the study of the effect of chronic pain itself as well as treatments such as acute and chronic opioid therapy on driving safety. Although safety is clearly an important issue, the influence of chronic pain and its impact on driving patterns has not been studied. Multiple facets of driving, including frequency of driving, need for driving, the environmental conditions in which driving takes place, the distances driven, driving barriers, and vehicle adaptations, may all be influenced by the effects of chronic pain. The results of this cross-sectional survey indicate that chronic pain may play a role in both the ability or inability to drive as well as influencing driving patterns for those who do drive. This study is the first to examine differences between drivers and nondrivers who have chronic nonmalignant pain. A total of 79% of respondents with chronic nonmalignant pain drive. This rate is lower than the rate of driving in the general population, with 86% of Canadians holding a valid driver’s license and presumed to be driving [39,40]. The rate of driving in our study is greater than the rate of driving in individuals 65 and older. In this latter population, 75% have a valid driver’s license, and 60% drive a motor vehicle [41]. When we compared the demographics of drivers with nondrivers, we found that women with chronic pain are less likely to drive compared with men. However, for other factors such as age, level of education, marital status, and
urban versus rural living environment, there was no significant difference between these groups. Overall, nondrivers appear to be experiencing more pain on a day-to-day basis and, parallel to this, have more associated disability. Although pain alone would certainly be expected to affect multiple factors on the PDI score, it is certainly possible that limitations caused by an inability to drive could have a secondary influence on the items, including recreation, social, occupation, and even home responsibilities in which the independent use of a vehicle could play a significant role in performing these activities to their fullest. Interestingly, for activities potentially less dependent on the ability to drive, such as sexual behavior and life support activities, there was no significant difference between drivers and nondrivers on these items. Other factors, such as pain duration, depressive symptomatology, and pain location, did not vary significantly between groups, although there was a trend for mood to be lower among nondrivers. For those who do continue to drive, the 2 main issues that seem to be identified include (1) comfort and vehicle adjustments to maximize function, and (2) changes in driving patterns as a result of chronic pain. Most respondents indicated that they use car adaptations to help accommodate some of the pain that they are experiencing. Although the most common adaptations used were automatic transmission, 4-door vehicles, and automatic windows, these features often tend to be standard in vehicles in North America. However, some minor adaptations are clearly used to assist with pain limitations, such as seatbelt, gear stick, and pedal modifications, which each had a low frequency of use, similar to the findings of Cranney et al [33]. Despite the low use of these adaptations, a high proportion of drivers with chronic pain identify problems entering and positioning themselves within the vehicle where challenges are presented with opening and closing doors, getting into the driver seat, and even putting on their seatbelt. More Table 6. Frequency of use of car options and adaptations Option/Adaptation (N ⴝ 176) Automatic transmission 4-Door vehicle Automatic windows Additional back or seat support Power adjustable seat Remote starter Sliding doors Wide rear-view mirror or extra mirrors Padded/covered steering wheel 2-Door vehicle Other Key turners “Push-down” gear stick or lengthened gear stick Modified seatbelt mechanism Pedal modifications
No. (%) of Subjects 160 (90.9) 154 (87.5) 140 (79.5) 93 (52.8) 74 (42.0) 52 (29.5) 39 (17.0) 29 (16.5) 26 (14.8) 20 (11.4) 18 (10.2) 15 (8.5) 4 (2.3) 2 (1.1) 1 (0.6)
PM&R
concerning is the fact that driving actions themselves are adversely affected by pain and physical limitations in situtations in which drivers report limitations with actions such as sitting for any length of time, reversing the vehicle, performing shoulder checks, and merging with traffic. Although the significance of these findings is not completely clear because there is no direct control group, our study results yielded findings similar to those in the crosssectional survey by Cranney et al [33], in which 542 patients with rheumatoid arthritis were assessed. The respondents in this study indicated that the most limiting symptoms for driving were pain (57%) and stiffness (51.3%). Subjects further reported difficulty with activities performed both in preparation for and during driving. Similar to our study, the authors identified a high proportion of patients (40.2% vs 37.3% in our study) having difficulty with opening and closing doors. The percentage of patients having difficulty with reaching for the seatbelt in the Cranney et al study (38.1%) is also similar to that quoted in our study (47.6%). In our study, there was a much higher percentage of patients (66.5%) who had difficulty with getting into the driver’s seat, whereas this did not seem to affect the population as much (36.6%) in the Cranney et al study. This difference likely reflects the area of pain affected most in our study being the neck or back. Accordingly, in the study by Cranney et al [33], there was a much higher percentage of patients with difficulty turning the key/ignition (41.6%) compared with that found in our study (7.5%). This again reflects the disability in hand function specific to the rheumatoid arthritis population, which is not as prevalent in our population with chronic pain. Interestingly, 3 of the top 4 most difficult activities during driving are the same in our study and in the study by Cranney et al [33], ie, sitting for any length of time, making shoulder checks, and reversing the vehicle. The only activity in the top 4 most difficult activities during driving that differs in the 2 studies is gripping the wheel in the Cranney et al study [33] and merging with traffic in our study, which would require shoulder checking likely affected by neck and back discomfort. This finding again highlights the disability-specific problem with driving encountered in different populations. When compared with a sample of healthy older drivers (mean age 78 years) [42], drivers with chronic pain reported greater levels of difficulty with turning the steering wheel (13.3%) or depressing the gas pedal or brakes (16.1%) versus the difficulty encountered by older drivers (4.3% report of problem for each task). The percentage of elderly drivers having difficulty with shoulder checks when backing up was 28.7%, whereas the percentage of subjects in our study having difficulty with making shoulder checks is approximately twice as high at 56.9%. The higher percentages of patients having driving difficulties seen in the chronic pain population compared with the older, healthy drivers seem to indicate that chronic pain poses more challenges to driving than does advanced age. Therefore, these results imply that
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chronic pain should be considered similarly to other medical conditions, which are often known to be more prevalent with increasing age, when driving ability, comfort, and safety are assessed. Equal if not more research efforts need to be directed to how chronic pain affects driving. A total of 18.4% of our respondents were not driving currently, compared with 7.8% of the subjects in the survey by Cranney et al [33]. Almost 6% of our respondents reported an accident in the previous year. This percentage appears to be greater than the 8% in the previous 5 years reported by Cranney et al [33]. The collision rate data are not comparable because they are based on self-report, but they may indicate that persons with chronic pain do face more difficulties with driving. This has not been identified as a potential problem even in more recent reviews of chronic illnesses and impact on driving [43]. A control group of persons without chronic pain is not available for direct comparison of accident rates with the chronic pain patients group in our study. Two recent reviews do help to put crash records in perspective. In a comprehensive review by Charlton et al [44], the relative risks of crash for most medical conditions were summarized; however, chronic pain as a condition was not specifically identified. Charlton et al [44] did identify that relative risk for crash was slightly elevated (relative risk 1.1-2.0) for the category of drivers with physical impairments, which may most closely resemble drivers with chronic pain conditions. In a review, Marshall [45] also outlined the various relative risks of crash for different medical conditions but did not identify chronic pain as a specific condition. Although relative rates cannot be calculated, the accident rate derived from our study (4.6 accidents per million kilometers driven) can be assessed in light of the collision rate published by the Ontario Ministry of Transportation of 1.9 accidents per million kilometers travelled [46]. Our accident rate in chronic pain patients of 4.6 accidents per million kilometers driven is similar to the self-reported rate found in a sample of healthy older drivers [42], where the accident rate was observed to be 4.1 accidents per million kilometers driven. Although a direct comparison with a control group of subjects without chronic pain is not available in our study, drivers with chronic pain seem to have a moderately high crash risk compared with the general population and compared with individuals with some other medical conditions that are known to have an impact on function. Only 9% of our respondents were aware of driving assessment programs, compared with 15.5% of the patients in the survey by Cranney et al [33]. The lower proportion in our study may be attributable to the perception of health care professionals treating patients with chronic pain that their difficulties with driving do not warrant a formal assessment. Health care professionals may not see the need for patients with these difficulties to receive advice and counseling from the physician and/or therapist. Another possible
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explanation is that driving assessment programs are geared toward assessing functional driving ability after an acute event such as a stroke or spinal cord injury and are less focused on chronic disability, where the impairment is not as immediately evident. In the United States, there are educational programs such as CarFit, which is designed to help older drivers determine how well their vehicles “fit” them, to promote driver safety and community mobility (http://www.car-fit.org). Examples of areas addressed in this program include mirror adjustment and foot positioning on the gas and brake pedals. Such an educational program could be beneficial for patients with chronic pain, helping them to minimize disability and maximize safety. As in the study by Cranney et al [33], only a small proportion of our respondents (2.4%) were eventually referred for a driving assessment. Lack of referral to a driver assessment center may be attributable to costs associated with such centers. Another possible reason is that in Canada, physicians and patients alike probably do not regard chronic pain as having a major impact on driving. Disability from chronic pain is generally not regarded as a reportable condition by most physicians. In contrast, in Australia, an unconditional license is not issued if chronic pain is present that interferes with concentration or results in restriction/loss of joint movement that impairs driving. A conditional license may be issued only after a practical assessment [43]. When the effect of chronic pain on driving is not readily acknowledged, management or referrals to appropriate resources to help patients improve their driving ability, comfort, and accessibility will not take place. Potential study limitations include the self-reported nature of the data. Furthermore, our findings may not be generalizable to all persons with chronic pain because of the selection bias of choosing patients with chronic pain referred to a tertiary care rehabilitation center. Having a driver’s license at one point in the subject’s life was not an inclusion criterion. In addition, there may be biases, including selfselection, attributable to pain level or disability level and exclusion from the study attributable to language barrier. The fact that there is no information on the subjects who refused to participate in the survey could potentially affect the external validity of the study. The lack of a control group of subjects without chronic pain is another limitation. Establishing the relationship between chronic pain and driving patterns is an important first step in an attempt to improve the overall mobility and quality of life of chronic pain sufferers. The results of our study call for future research initiatives on controlled studies investigating the relationship between chronic pain and driving. This will in turn lead to studies in the future exploring interventions to make driving more accessible and comfortable for persons with chronic pain.
CONCLUSIONS Most people with chronic pain continue to drive and overall appear to have better functioning than those who cannot
SELF-REPORTED ISSUES WITH DRIVING AND CHRONIC PAIN
continue driving because of chronic pain. Despite being able to drive, a significant proportion of drivers with chronic pain are facing challenges not only with driving the vehicle but also with entering and positioning themselves within the vehicle. The implications with regards to safety and crash risk for those who have chronic pain remain unknown. Our results suggest that, not surprisingly, chronic pain does have an impact on driving. However, it appears to be generally unrecognized as a factor for driving other than when the implications of narcotic use are considered. Future research into the effect of chronic pain on driving, including the completion of controlled studies, is needed.
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17. Lorenz J, Bromm B. Event related potential correlates of interference between cognitive performance and tonic experimental pain. Psychophysiology 1997;34:436-445. 18. Crombez G, Eccleston C, Baeyens F, Eelen P. Habituation and the interference of pain with task performance. Pain 1997;70:149-154. 19. Crombez G, Eccleston C, Baeyens F, Eelen P. The disruptive nature of pain: An experimental investigation. Behav Res Ther 1996;34:911-918. 20. Sjogren P, Olsen AK, Thomsen AB, Dalberg J. Neuropsychological performance in cancer patients: The role of oral opioids, pain and performance status. Pain 2000;86:237-245. 21. McCracken LM, Iverson G. Predicting complaints of impaired cognitive functioning in patients with chronic pain. J Pain Symptom Manage 2001;21:392-396. 22. Munoz M, Esteve R. Reports of memory functioning by patients with chronic pain. Clin J Pain 2005;21:287-291. 23. Roth RS, Geisser ME, Theisen-Goodvich M, Dixon PJ. Cognitive complaints are associated with depression, fatigue, female sex, and pain catastrophizing in patients with chronic pain. Arch Phys Med Rehabil 2005;86:1147-1154. 24. Brown SC, Glass JM, Park DC. The relationship of pain and depression to cognitive function in rheumatoid arthritis patients. Pain 2002;96: 279-284. 25. Weiler JM, Bloomfield JR, Woodworth GG, et al. Effects of fexofenadine, diphenhydramine, and alcohol on driving performance. Ann Intern Med 2000;132:354-363. 26. Jones JG, McCann J, Lassere MN. Driving and arthritis. Br J Rheumatol 1991;30:361-364. 27. Duong BD, Kerns RD, Towle V, Reid MC. Identifying the activities affected by chronic nonmalignant pain in older veterans receiving primary care. J Am Geriatr Soc 2005;53:687-694. 28. Veldhuijzen DS, van Wijck AJM, Wille F, et al. Effect of chronic nonmalignant pain on highway driving performance. Pain 2006;122: 28-35. 29. Dimension Research Inc. Sample size for proportion calculator. 2005. Available at: http://www.dimensionresearch.com/resources/calculators/ sample_size.html. Accessed November 1, 2006. 30. Jensen MP, Turner JA, Romano JM, Fisher LD. Comparative reliability and validity of chronic pain intensity measures. Pain 1999;83: 157-162. 31. Kroenke K, Spitzer RL, Williams JB. The PHQ-9: Validity of a brief depression severity measure. J Gen Intern Med 2001;16:606-613. 32. Owsley C, Stalvey B, Wells J, Sloane ME. Older drivers and cataract: Driving habits and crash risk. J Gerontol A Biol Sci Med Sci 1999;54: M203-M211. 33. Cranney AB, Harrison A, Ruhland L et al. Driving problems in patients with rheumatoid arthritis. J Rheumatol 2005;32:2337-2342. 34. Jerome A, Gross RT. Pain Disability Index: Construct and discriminant validity. Arch Phys Med Rehabil 1991;72:920-922.
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35. Bennett RM, Burckhardt CS, Clark SR, O’Reilly CA, Wiens AN, Campbell SM. Group treatment of fibromyalgia: A 6 month outpatient program. J Rheumatol 1996;23:521-528. 36. Haley WE, Turner JA, Romano JM. Depression in chronic pain patients: Relation to pain, activity, and sex differences. Pain 1985;23:337-343. 37. Smith TW, O’Keeffe JL, Christensen AL. Cognitive distortion and depression in chronic pain: Association with diagnosed disorders. J Consult Clin Psychol 1994;62:195-198. 38. Dillman DA. Mail and Internet Surveys: The Tailored Design Method. 2nd ed. New York: Wiley; 2000. 39. Transport Canada. Number of licensed drivers by gender and age. 2006. Available at: http://www.tc.gc.ca/eng/roadsafety/tp-tp33222006-page11-594.htm. Accessed September 1, 2011. 40. Age and Sex Highlight Tables. 2006 Census. Statistics Canada Catalogue no. 97-551-XWE2006002. Ottawa, ON, Candada. Released July 17, 2007. 41. Statistics Canada, Canadian Community Health Survey—Healthy Aging, 2009. Available at: http://www.statcan.gc.ca/pub/16-002-x/16002-x2010004-eng.pdf. Accessed October 31, 2011. 42. Marshall SC, Molnar F, Man-Son-Hing M, Wilson KG, Stiell I. The Canadian Safe Driving Study—phase I pilot: Examining logistical barriers to the full cohort study. Paper presented at the International Conference on Aging, Disability and Independence, St. Petersburg, Florida, 2006, February. 43. Charlton J, Koppel S, O’Hare M, et al. Influence of chronic illness on crash involvement of motor vehicle drivers. Report No. 213. Clayton, Victoria, Australia: Monash University Accident Research Centre; 2004. 44. Charlton J, Koppel S, Odell M, et al. Influence of chronic illness on crash involvement of motor vehicle drivers. Report No. 300. Clayton, Victoria, Australia: Monash University Accident Research Centre; 2010. 45. Marshall SC. The role of reduced fitness to drive due to medical impairments in explaining crashes involving older drivers. Traffic Injury Prev 2008;9:291-298. 46. Ontario Ministry of Transportation. Ontario road safety annual report (ORSAR). 2007. Available at: http://www.mto.gov.on.ca/english/safety/ orsar/orsar07/collision.shtml. Accessed September 1, 2011. This CME activity is designated for 1.0 AMA PRA Category 1 Credit™ and can be completed online at me.aapmr.org. Log on to www.me.aapmr.org, go to Lifelong Learning (CME) and select Journal-based CME from the drop down menu. This activity is FREE to AAPM&R members and $25 for non-members.
CME Question Compared to people with chronic pain who continue to drive, those who stop driving: a. b. c. d.
have post high school education. are more likely to be female. have significantly shorter pain duration. have more likely been in an accident.
Answer online at me.aapmr.org
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