Improved Functional Capacity Evaluation Performance Predicts Successful Return to Work One Year After Completing a Functional Restoration Rehabilitation Program

PM R 7 (2015) 365-375

www.pmrjournal.org

Original ResearcheCME

Improved Functional Capacity Evaluation Performance Predicts Successful Return to Work One Year After Completing a Functional Restoration Rehabilitation Program Lisa Fore, OTR, Yoheli Perez, PT, DPT, Randy Neblett, MA, LPC, BCB, Sali Asih, MS, Tom G. Mayer, MD, Robert J. Gatchel, PhD, ABPP

Abstract Objective: To evaluate whether functional capacity evaluation (FCE) scores are responsive to functional restoration treatment, and to assess the ability of FCEs at program discharge to predict work outcomes. Design: An interdisciplinary cohort study of prospectively collected data. Setting: A functional restoration center. Patients: A consecutive sample of 354 patients with chronic disabling occupational musculoskeletal disorders (CDOMDs) completed a functional restoration program consisting of quantitatively directed exercise progression and multi-modal disability management with interdisciplinary medical supervision. Methods: Each patient participated in an FCE at admission and discharge from treatment. The results of each FCE yielded the physical demand level (PDL) at which patients were functioning. Patients were initially divided into 5 PDL groups, based on job-ofinjury lifting, carrying, and pushing/pulling requirements, for the pre- to posttreatment responsiveness analyses. Patients were subsequently divided into 5 PDL groups, based on their performance on the FCE upon program completion. Main Outcome Measures: Outcome measures included admission-to-discharge changes in PDLs and 2 specific FCE lifting tasks: isokinetic lifting; and the Progressive Isoinertial Lifting Evaluation (PILE). Socioeconomic outcomes were also evaluated, including post-discharge work return and work retention 1-year after treatment completion. Results: Overall, 96% of the patients demonstrated improvement in their PDLs from admission to discharge. A majority of patients (56%) were able to achieve a discharge PDL that was comparable to their estimated job-of-injury lifting requirement or higher (P < .001). Lifting ability improved from admission to discharge by approximately 50% (all P < .001). Discharge PDLs predicted both work return (P < .001) and work retention (P < .001) 1 year later. Conclusions: FCE scores were responsive to functional restoration treatment, and the associated discharge PDLs predicted work return after treatment completion and work retention 1 year later.

Introduction A functional capacity evaluation (FCE) is a systematic measurement of a person’s ability to safely perform work activities. FCEs are widely used as part of the evaluation component of the work-injury management system [1]. There are 2 general purposes of FCEs. First, they can be used to identify current limitations and levels of disability, to assist in treatment planning [2]. Second, job-specific FCEs can be used to predict an injured worker’s safe functional abilities, so that the worker can make a successful return to employment. In

a recent study using a semi-structured interview, both patients and return-to-work experts found FCE data to be useful in assisting with return-to-work planning [3]. The results of an FCE yield a physical demand level (PDL), which is categorized into sedentary, light, medium, heavy, and very heavy, based upon criteria found in the U.S. Department of Labor’s Dictionary of Occupational Titles [4]. Although a PDL is determined, in large part, by the amount of weight that the patient is able to lift, carry, push, or pull in materials-handling tasks, it usually represents more than just an estimation of physical abilities. FCE performance can be

1934-1482/$ - see front matter ª 2015 by the American Academy of Physical Medicine and Rehabilitation http://dx.doi.org/10.1016/j.pmrj.2014.09.013

366

Improved Functional Capacity Predicts Work Return

influenced by psychosocial factors such as effort, motivation, pain intensity, perceived disability, fearavoidance beliefs, sense of self-efficacy, and depressive symptoms [5-8]. In fact, studies have found that combining materials-handling tasks with self-report information (such as pain ratings) was associated with increased predictive validity of FCEs [9-12]. Varied results have been found on the value of performance-based measures for predicting work outcomes. The results are especially ambiguous because there has been no standard method for defining work outcomes or for determining which FCE variables to evaluate [12]. Some authors have demonstrated that trunk strength [13] and the amount of weight lifted during lifting tasks was predictive of work return [14,15]. Some authors have found that passing all prescribed FCE tests [16,17] or a combination of passing all FCE tests and a moderate or lower pain level [18] predicted work return. Carrying and lifting ability has also shown a weak prediction of posttreatment work retention [19]. Other authors have found that both lifting tasks and the number of failed FCE tests did not predict work retention [20-22]. The association between total FCE scores and work outcomes is difficult to determine, because most studies have evaluated only individual components of FCEs. Moreover, although standard FCE protocols do exist, there is significant variation in how different treatment facilities perform them, which specific tests are used, and how PDLs are determined [23,24]. For instance, some authors have determined the PDL from a single floor-to-waist lift test [25], some from the combination of a dead lift and an overhead press [26], and others from a combination of several FCE variables, including lifting tests and the number of failed tests [7]. In addition, few studies have used a job demands analysis to establish job-specific FCEs based on the minimal performance criterion that is required for an individual to perform his or her target job [12]. It should also be noted that, although FCEs are often used to help with treatment planning, we found relatively few studies that evaluated the treatment responsiveness of FCE scores. Three studies found pre- to posttreatment FCE improvements in populations of chronic pain patients with worker’s compensation claims who participated in functional restoration [23] and work hardening programs [25,26]. More studies are needed in this area, which was 1 of the major purposes of the present investigation. Because of the limited research data on FCEs as a treatment-responsiveness measure, and the limited data on the predictive value of performing a full FCE to determine a PDL, versus simply assessing lifting capacity from a single lifting test, one may question the time- and cost-effectiveness of FCEs. Both the lack of standardization and the lack of evidence supporting their validity have been primary criticisms of FCEs [27]. The present investigation was designed to increase the

validity of FCEs by systematically evaluating the treatment responsiveness of FCE scores. In the present study, FCE data were evaluated in a chronic disabling occupational musculoskeletal disorder (CDOMD) population who participated in a functional restoration treatment program. CDOMD patients represent the 10% of injured workers who did not respond favorably to previous surgical and nonsurgical treatments and have developed chronic pain and disability from activities of daily living [28,29]. The typical CDOMD patient is physically deconditioned, financially and interpersonally stressed, fear-avoidant, and significantly more likely than the general population to meet diagnostic criteria for DSM IV Axis I and Axis II mental health disorders [30]. The functional restoration program in the present study used a biopsychosocial treatment model, which views dysfunction and occupational illness as a complex interaction of biological, psychological, and social variables [31,32]. The FCE is an essential component of the functional restoration program for quantifying function and guiding treatment. The FCE model in the present study used a standardized, evidence-based approach for assessing and quantifying function. PDLs were determined from the cumulative results of all individual FCE tests that were performed, and the discharge FCEs were geared toward each patient’s posttreatment job plan [33-36]. Three components of the FCE were evaluated in the present study, including admission and discharge PDLs and 2 specific lifting tasks: isokinetic lifting and the Progressive Isoinertial Lifting Evaluation (PILE). These 2 lifting components of the FCE were chosen for separate evaluation because they are well studied and were used in every FCE, regardless of the individual patient’s compensable body part(s) [35-41]. The present study also assessed how well discharge PDLs predicted socioeconomic outcomes, including post-discharge work return and work retention 1 year later. Furthermore, the ability of discharge PDLs to predict work outcomes over and above other variables that are known to affect work outcomes, including length of disability, work status at admission, pain intensity, depressive symptoms, and perceived disability [42-45], were assessed. In addition, the present study assessed how well discharge PDLs predicted the job-specific lifting requirements for those patients who had successfully retained work at 1 year postdischarge. Methods Participants A consecutive cohort of 354 CDOMD patients, with work-related injuries to at least 1 spinal or extremity area, completed a functional restoration program at a regional rehabilitation center between 2009 and 2010. Upon admission, 24% of patients were working “light

L. Fore et al. / PM R 7 (2015) 365-375

duty” with physical or part-time restrictions, and 76% of patients were totally disabled from work. All patients were discharged from treatment with a work plan. The inclusion criteria for participation in this functional restoration program were as follows: work-related injury claim occurring at least 4 months before entry into the program; chronic disability remaining after acute nonoperative care and/or secondary care; surgery not a clear option or not providing resolution; persistent severe pain and functional limitations; and ability to communicate in English or Spanish. Functional Restoration Program All patients participated in an interdisciplinary functional restoration program with treatment duration of approximately 160 hours over 4 to 8 weeks. The physical training portion of the program was supervised by both physical and occupational therapists, aimed at restoring muscular strength, flexibility, endurance, and cardiovascular fitness. Exercise progression for each patient was guided by his or her quantitative FCE scores at admission and periodic physical testing throughout the treatment program. The FCE testing set the starting training levels, which were subsequently adjusted as training progressed, and they were normed for each individual based on age, gender, and body mass index (BMI) to provide a safe and measurement-driven exercise progression process. At discharge, all patients were provided with a home program for continued fitness maintenance. The exercise program was administered in conjunction with a multimodal disability management program, which included injury education, individual counseling, group therapy, biofeedback, stress management training, and vocational reintegration. The functional restoration program was medically directed, with physicians available to provide medication management (particularly opioids and psychotropic medications), rehabilitation supervision, and assessment of surgical options when necessary [28,46,47]. This program has consistently demonstrated positive outcomes for patients with CDOMDs [48-54]. Data Collection An initial evaluation consisted of a physical examination, a medical history, a medical case management disability assessment, a psychosocial assessment including a patient-report test battery, and a quantitative FCE. Demographic data and socioeconomic information, including lifting requirements (number of pounds of frequent and occasional lifting) from the job of injury were also collected as part of the intake interview. The job-of-injury lifting requirements (sedentary, light, medium, heavy, and very heavy) were determined by published standardized job descriptions (eg, such as a city firefighter), specific information from

367

the employer, and/or patient report. Included in the patient report test battery and analyzed in the present study were the Pain Visual Analog Scale (PVAS; scored from 0 to 10) [42] the Beck Depression Inventory (BDI; scored from 0 to 63) [55], and the Pain Disability Questionnaire (PDQ; scored from 0 to 150) [56]. The PVAS assessed each patient’s pain level in response to his or her injury. The PDQ assessed perceived disability with daily activities. The BDI assessed depressive symptoms, which are commonly reported by CDOMD patients. For each measure, higher scores indicated more severe symptoms. Upon completion of the functional restoration program, an identical test battery and FCE were completed. Socioeconomic outcome data were collected through a structured interview 1 year after functional restoration program discharge [57]. These outcomes included work return (defined as obtaining employment within the year after treatment discharge) and work retention (continuation of employment 1 year after treatment discharge). Health care use outcome variables included the number of surgeries to the original site(s) of the claimed injury, the percentage of patients seeking health care from a new provider, and the number of visits to a new provider. A third outcome domain involved lost work time because of a new workers’ compensation injury claim to the original injured body part(s). Work return/retention lifting requirements were collected from those patients who had returned to, and who had retained, work 1 year postdischarge. Because all of the data used in the present study were part of the patients’ standard medical files, the study was granted exemption status by the institutional review board of the University of Texas at Arlington. Functional Capacity Evaluation The components of the FCE are detailed in Table 1. Positional activities listed in Table 1 are based on definitions provided by the U.S. Department of Labor’s Dictionary of Occupational Titles [4]. Each FCE test was intended to document an individual’s functional ability, as observed from the onset of evaluation to completion of the test. Positional tolerances were observed throughout testing and were cross-tested for consistency. Testing for all patients included a musculoskeletal examination, range-of-motion (ROM) assessment, isokinetic strength testing, and lifting evaluation. Additional positional tasks were chosen based on the injured body part(s) and physical demands for a target job. Testing was individualized for each patient. An FCE was performed at the beginning and at the conclusion of the treatment program for each patient. At treatment admission, appropriate positional tests were chosen based on the physical demands, including frequent and occasional lifting requirements, from the job-of-injury. At treatment discharge, appropriate positional tests were chosen based upon the physical

368

Improved Functional Capacity Predicts Work Return

Table 1 Brief description of functional capacity evaluation components Task

Description

Lifting e PILE Floor to waist Waist to shoulder Lifting e computerized isokinetic lift test (Biodex System 4) Floor to waist Waist to shoulder Lifting e overhead lift

Standardized 4-repetition/weight test at increasing weight increments

Bilateral carry Push and pull Position tolerance Range of motion Computerized isokinetic strength test (Biodex System 4)

Isokinetic dynamic lifting device used at 20 inches per second and 30.6 inches per second to measure lifting capabilities

Dowel wooden box taken from standardized shoulder level shelf (54 inches) and raised to arms fully extended; progress in weight increments to maximum 30 Feet forward and back (requires pivoting at endpoint) at waist height; progress in weight increments to maximum (5 lb females; 10 lb males) Static full body push and full body pull; 3 repetitions each Sitting, standing, bending, crawling, crouching, walking, twisting, climbing, balancing, stooping, kneeling, reaching, handling, fingering Range of motion of individual affected body joints Strength testing of individual affected body joints

PILE ¼ Progressive Isoinertial Lifting Evaluation.

demands, including frequent and occasional lifting requirements, for a planned work-return position (either the same as the job of injury or a new employment position). The lowest performance level on any individual test determined the patient’s current physical demand level (PDL). Thus, if a patient scored heavy on some tests and medium on others, a medium PDL level was chosen. Patients were briefly instructed on how to perform each test, with standardized instructions provided by a certified evaluator. To ensure competence, all instructors participated in yearly FCE training, and all were Biodex [58] certified. In appropriate areas, the evaluator first demonstrated each test. Patients were asked to perform the tests to their maximum safe ability. Individual tests were stopped because of the following: psychophysical factors (patient stopped because of pain, inhibition, or fear avoidance); cardiovascular factors (met or exceeded 85% of patient’s agerelated maximum, or 120 beats per minute if on a b blocker); safety factors (the evaluator observed unsafe biomechanical factors, such as excessive accessory muscle recruitment, inappropriate lifting speed, or improper counterbalancing); or test completion. A heart rate monitor (Polar Electro, Oulu, Finland) was worn by the patients throughout the test procedures. Physical Demand Level From the cumulative results of the FCE, patients were categorized into 1 of the 5 PDL categories specified below, as defined by the US Department of Labor Employment and Training Administration.
Sedentary: Exerting a negligible amount of force frequently (from one-third to two-thirds of the time) and/or up to 10 pounds of force occasionally (up to

one-third of the time) to lift, carry, push, pull, or otherwise move objects, including the human body.
Light: Up to 10 pounds of frequent and/or 20 pounds of occasional lifting.
Medium: Up to 25 pounds of frequent and/or 50 pounds of occasional lifting.
Heavy: Up to 50 pounds of frequent and/or 100 pounds of occasional lifting and/or 10 to 20 pounds of force constantly to move objects.
Very Heavy: More than 50 pounds of frequent and/or 100 pounds of occasional lifting and/or in excess of 20 pounds of force constantly to move objects. Lifting Tests Lifting tests were primary components of all FCEs and helped to determine each patient’s PDL. The isokinetic lifting performance measurement is a dynamic strength test that holds the velocity constant and allows for objective and safe measurement of forces exerted at each point along the height spectrum as the subject attempts to exceed the preselected examination speed [38,59,60]. Isokinetic lifting was measured in the current study at 20 inches per second with a Biodex System 4 Lift Attachment [58]. This isokinetic lift test included floor-to-waist and waist-to-overhead lifts. The PILE is another type of dynamic strength test, which uses a standardized protocol involving increases in load increments being lifted from various heights [39,40]. Specifically, the PILE involves lifting a receptacle filled with varying amounts of weights from floor-to-waist and from waist-to-shoulder height. The amount of weight is increased incrementally at specific rates, to provide a motionetime measurement. Unlike isokinetic lifting, the PILE does not hold the velocity constant, which allows both agility and lifting strength to be measured.

L. Fore et al. / PM R 7 (2015) 365-375

The lifting raw scores were converted to a percentage of normal scores. Percentage of normal scores were calculated by dividing the raw scores by the patient’s body weight (which was adjusted by actual versus ideal body weight), multiplying by 100, and then dividing by a normative score, while controlling for age and gender. This normative database and method for determining percentage of normal on the PILE and isokinetic lifting test have been detailed elsewhere [36,38,46,59,61,62]. Statistical Analyses The statistical analyses were performed using SPSS version 19 software. c2 Tests for independence were used for categorical variables, whereas analyses of variance were used for continuous variables. In additional, repeated-measures analyses of variance were used to analyze pre- to posttreatment changes. Finally, a binary logistic regression analysis was performed to further evaluate whether discharge PDLs were significant predictors of work outcomes. Results Table 2 provides patient demographic information. Patients were divided into 5 groups (sedentary, light, medium, heavy, and very heavy), based on the frequent and occasional lifting requirements of their job-ofinjury. The majority of female patients had worked at sedentary, light, and medium jobs. In contrast, most male patients had worked at heavy and very heavy jobs. Lighter jobs were associated with increasing age (P < .001). Significant differences were found among the groups in length of disability, which represents the total number of months between the injury date and the beginning of treatment (P ¼ .009). Those with sedentary and light jobs had the longest lengths of disability. Table 3 presents the patients’ PDLs upon admission to the functional restoration program compared to their job-of-injury lifting requirements. Significant differences were found between the job-of-injury lifting requirements and prefunctional restoration program PDLs (P ¼ .006). Slightly more than one-half of the patients (52%) tested at a sedentary PDL. Only 1 person achieved a heavy PDL, and no patient achieved a very heavy PDL. Approximately one-half of the patients with medium, heavy, or very heavy job-of-injury lifting requirement were performing at a sedentary PDL. Table 4 presents patients’ discharge PDLs compared to their job-of-injury lifting requirements. Significant differences were found between the job-of-injury lifting requirements and discharge PDLs (c2 ¼ 132.13, P < .001). A large percentage of patients with medium (69.7%) and heavy (53%) job-of-injury lifting requirements achieved a comparable PDL at the end of treatment. All patients (100%) with sedentary job-ofinjury lifting requirements, and the majority of patients

369

(58.6%) with light job-of-injury lifting requirements, demonstrated higher discharge PDLs than their job-ofinjury lifting requirements. Table 5 presents the lifting ability of patients, presented as a percentage of normal, at admission and discharge from the functional restoration program. Large pre- to posttreatment changes in mean percentages of normal (all P < .001) were found on all lifting tests. Table 6 presents the 1-year socioeconomic outcomes based on PDL categories at discharge. The discharge PDLs were significantly associated with work return within 1 year of treatment completion (P < .001). Higher discharge PDLs were associated with increased odds of returning to work. The percentage of patients reporting work return ranged from 73.1% in the light PDL group to 95.7% in the very heavy PDL group. In determining the odds ratios of returning to work, the light PDL group was used as a reference to compare with the other PDL groups. So, compared to the light PDL group, the odds ratios for patients with medium, heavy, and very heavy PDLs for returning to work were 1.4 (95% confidence interval [CI] ¼ 0.51-3.68), 5.6 (95% CI ¼ 1.75-17.86), and 9.0 (95% CI ¼ 0.99-82.34), respectively. Similarly, for those patients who had returned to work, discharge PDLs were significantly related to work retention 1 year after treatment completion (P < .001). The odds ratios for patients with medium, heavy, and very heavy PDLs in retaining work, when compared to the light PDL group, were 2.0 (95% CI ¼ 0.83 -4.87), 4.0 (95% CI ¼ 1.56-10.26), and 3.4 (95% CI ¼ 0.93-12.45), respectively. As seen in Table 6, discharge PDLs were only useful for predicting the work status outcomes and were not useful for predicting the other health care use outcome variables. A binary logistic regression analysis was run to determine whether the discharge PDLs significantly predicted work outcomes over and above other factors that can influence work outcomes, rather than just demonstrating a relationship, as the above c2 analyses did. The specific factors that were controlled for in this analysis were length of disability and work status at treatment admission, and pain intensity, depressive symptoms, and perceived disability at treatment discharge. Results showed that work status at admission (Wald test ¼ 6.89, P ¼ .009) and pain intensity at discharge (Wald test ¼ 5.00, P ¼ .025) significantly predicted work return. Specifically, working upon admission (OR ¼ 5.4, 95% CL ¼ 1.53-18.80) and lower pain intensity scores (OR ¼ 1.3, 95% CL ¼ 1.03-1.56) increased the chance of returning to work. Results showed that the addition of the discharge PDL scores (Wald test ¼ 6.4, P ¼ .011) was a significant predictor of work return, over and above these other factors, and increased the predictive value of the work return model [c2 (1, 6) ¼ 43.29, P < .001]. Furthermore, work status at admission (Wald test ¼ 7.99, P ¼ .005) and pain intensity at discharge (Wald test ¼ 9.93, P ¼ .002)

370

Improved Functional Capacity Predicts Work Return

Table 2 Demographic information by the U.S. Department of Labor’s Dictionary of Occupational Title’s Job-of-Injury Lifting Requirements (n ¼ 354) Job-of-Injury Lifting Requirements Variable

Sedentary n¼7

Light n ¼ 29

Medium n ¼ 89

Heavy n ¼ 115

Very Heavy n ¼ 114

Age, mean (SD) Gender, n (% male) Type of injury, n (%) Cervical only Thoracic/lumbar only Extremities only Multiple spinal Spinal þ additional injury Other Ethnic group, n (%) White African American Hispanic Others Length of disability,‡ mo, mean (SD) Total temporary disability,§ mo, mean (SD) Pretreatment surgery, n (%)

51.3 (8.6) 49.3 (10.8) 47.0 (9.9) 45.4 (9.9) 41.4 (10.1) 6.63 1 (14.3%) 10 (34.5%) 37 (41.6%) 81 (70.4%) 99 (86.8%) 67.41 31.64 0% 0% 3 (3.4%) 5 (4.3%) 2 (1.8%) 3 (42.9%) 3 (10.3%) 27 (30.3%) 38 (33.0%) 35 (30.7%) 1 (14.3%) 10 (34.5%) 24 (27.0%) 38 (33.0%) 27 (23.7%) 1 (14.3%) 1 (3.4%) 5 (5.6%) 9 (7.8%) 9 (7.9%) 2 (28.6%) 12 (41.4%) 30 (33.7%) 24 (20.9%) 39 (34.2%) 0% 3 (10.3%) 0% 1 (0.9%) 2 (1.8%) 18.84 2 (33.3%) 16 (66.7%) 38 (45.8%) 61 (55.5%) 54 (50.9%) 2 (33.3%) 5 (20.8%) 25 (30.1%) 19 (17.3%) 16 (15.1%) 2 (33.3%) 3 (12.5%) 16 (19.3%) 30 (27.3%) 32 (30.2%) 0% 0% 4 (4.8%) 0% 4 (3.8%) 44.1 (75.9) 31.4 (50.8) 16.8 (21.1) 18.2 (20.9) 18.8 (19.1) 3.42 10.1 (9.6) 11.6 (24.6) 10.1 (15.9) 11.9 (15.9) 12.3 (14.0) 0.27 2 (40%) 12 (46.2%) 31 (39.2%) 54 (51.9%) 58 (52.7%) 4.19

F/c2 Value P Value ES <.001 <.001 .047

0.07* 0.43† 0.15†

.092

N/A

.009 .895 .381

0.04* N/A N/A

PDL ¼ physical demand level. * Effect size (partial h2): small, 0.01; medium, 0.06; large, 0.14. † Effect size (Cohen’s W): small, 0.1; medium, 0.3; large, 0.5. ‡ Length of disability refers to the number of months between the date of injury and treatment admission. § Total temporary disability refers to the number of months not working between the date of injury and treatment admission.

significantly predicted work retention. Specifically, working upon admission (OR ¼ 2.8, 95% CL ¼ 1.35-5.74) and lower pain intensity score (OR ¼ 1.3, 95% CL ¼ 1.10-1.42) increased the chance of retaining work 1 year post discharge. The addition of the discharge PDL scores (Wald test ¼ 4.48, P ¼ .034) significantly predicted work retention over and above these other factors and increased the predictive value of the work retention model [c2 (1, 6) ¼ 37.38, P < .001]. Length of disability, depressive symptoms, and perceived disability at discharge were not found to be significant predictors of work return or work retention (P ¼ not significant [NS]). At treatment discharge, FCE results and PDLs were used to help with posttreatment job planning, to help ensure that each patient was able to perform at the appropriate PDL level for the lifting requirements of that individual’s target job. For those patients who had

returned to, and retained, work 1 year posttreatment, Table 7 presents the associations between discharge PDLs and the lifting requirements of their jobs. Approximately 47.1% of patients were working at jobs with comparable lifting requirements as their discharge PDLs, 39.3% were working at jobs with lower lifting requirements than their discharge PDLs, and 13.6% were working with higher lifting requirements than their discharge PDLs. Discussion As noted earlier, although FCEs are often used to help guide treatment planning, few studies to date have evaluated their treatment responsiveness [23,25,26]. The present investigation provides positive evidence for the treatment responsiveness of FCEs in a cohort of CDOMD patients who completed a functional restoration

Table 3 Physical demand levels (PDLs) by job-of-injury lifting requirements upon admission to the functional restoration program (n ¼ 354) Job-of-Injury Lifting Requirements Variable

Sedentary n¼7

Light n ¼ 29

Medium n ¼ 89

Heavy n ¼ 115

Very Heavy n ¼ 114

PDLs at treatment admission, n (%) Sedentary Light Medium Heavy Very heavy†

5 (71.4%) 1 (14.3%) 1 (14.3%) 0% N/A

18 (62.1%) 11 (37.9%) 0% 0% N/A

52 (58.4%) 26 (29.2%) 11 (12.4%) 0% N/A

51 (44.3%) 41 (35.7%) 22 (19.1%) 1 (0.9%) N/A

58 (50.9%) 30 (26.3%) 26 (22.8%) 0% N/A

* †

Effect size (Cohen’s W): small, 0.1; medium, 0.3; large, 0.5. No patients achieved a very heavy PDL upon program admission.

c2 Value

P Value

ES*

16.67

.006

0.13

L. Fore et al. / PM R 7 (2015) 365-375

371

Table 4 Physical demand levels (PDLs) by job-of-injury lifting requirements upon discharge from the functional restoration program (n ¼ 354) Job-of-Injury Lifting Requirements Variable

Sedentary n¼7

Light n ¼ 29

Medium n ¼ 89

Heavy n ¼ 115

Very Heavy n ¼ 114

PDLs at treatment discharge, n (%) Sedentary† Light Medium Heavy Very heavy

N/A 1 (14.3%) 6 (85.7%) 0% 0%

N/A 12 (41.4%) 14 (48.3%) 3 (10.3%) 0%

N/A 11 (12.4%) 62 (69.7%) 16 (18.0%) 0%

N/A 3 (2.6%) 47 (40.9%) 61 (53.0%) 4 (3.5%)

N/A 0% 42 (36.8%) 51 (44.7%) 21 (18.4%)

c2 Value

P Value

ES*

132.13

<.001

0.35

N/A ¼ not applicable. * Effect size (Cohen’s W): small, 0.1; medium, 0.3; large, 0.5. † No patients performed at sedentary PDL at treatment discharge.

program. At treatment admission, 82.7% of patients fell into either a sedentary or light PDL category. At treatment discharge, only 7.6% of patients were classified into a light PDL category, and no patients into a sedentary PDL category. Overall, 96% of CDOMD patients demonstrated improvement in PDL performance at the end of the functional restoration program, and 56.5% of the patients were able to achieve a discharge PDL that was comparable to or higher than their job-of-injury lifting requirements. Of those patients who were not able to achieve discharge PDLs comparable to their jobof-injury lifting requirements, a majority (80%) had discharge PDLs only 1 level below their job-of-injury lifting requirements. Furthermore, the means of the PILE and isokinetic lifting tests, 2 vital components of the FCE, improved from 24.3% to 37.2% of normal at admission to 80% to 85% of normal at discharge. The present study also evaluated how well discharge PDLs predicted return to employment after treatment completion and retention of employment approximately 1 year later. Upon program admission, 24% of patients were working with physical restrictions, doing “light duty,” and 76% of patients were not working. Within the year following treatment completion, 85% had returned to employment, and 73% had retained employment 1 year later. The percentage of patients who returned to work within the year after treatment discharge increased as discharge PDLs increased. Thus, for patients with discharge PDLs in the light, medium,

heavy, and very heavy range, 73.1%, 78.1%, 93.3%, and 95.7% of them (respectively) returned to employment after completing treatment. Of those who had returned to work, the percentage of patients retaining employment 1 year later increased as the discharge PDLs increased for the light (54.2%), medium (68.5%), and heavy (81%) groups. Patients in the very heavy group had slightly less success (78.3%) than the heavy group in retaining employment. Previous studies have shown that a number of factors can affect work outcomes after a functional restoration program, including the length of disability, work status at treatment admission, and patient-reported pain intensity, depressive symptoms, and perceived disability at treatment discharge [42-45]. In the present study, working upon admission and lower pain intensity scores at discharge predicted both work return and working retention. Discharge PDLs predicted work return and work retention even after controlling for these other factors. Higher postefunctional restoration physical fitness clearly equated with better work return and work retention outcomes. As a standard part of the functional restoration program, discharge FCE results were used to help with posttreatment job planning, to help ensure that patients were performing at the appropriate PDL levels for the lifting requirements of their target jobs. The present study analyzed how closely the discharge PDL was related to the job-specific lifting requirements for

Table 5 Changes in lifting ability from treatment admission to discharge* Pounds Lifted as Percentage of Normal Lifting Task Variable

Admission

Discharge

F Value

P Value

ES†

PILE, floor to waist, mean (SD) PILE, waist to shoulder, mean (SD) Isokinetic, lift floor to waist, mean (SD) Isokinetic, lift waist to overhead, mean (SD)

29.1% 37.2% 24.3% 31.3%

82.3% 81.5% 81.1% 85.6%

864.11 785.95 908.69 607.50

<.001 <.001 <.001 <.001

0.730 0.704 0.725 0.638

(28.2) (26.9) (29.6) (29.6)

(30.3) (25.5) (32.0) (40.0)

PILE ¼ Progressive Isoinertial Lifting Evaluation. * Amount of weight lifted, in pounds, was compared with a normative sample and converted into a percentage of normal. † Effect size (partial h2): small, 0.01; medium, 0.06; large, 0.14.

372

Improved Functional Capacity Predicts Work Return

Table 6 Socioeconomic outcomes, 1 year after treatment completion, by discharge physical demand levels (PDLs) (n ¼ 319) Discharge PDLs Sedentary n¼0

Variable †

Return to work, n (%) Work retention,‡ n (%) New surgery to original site, n (%) Seeking health care from new provider, n (%) No. of visits to new provider, mean (SD) Case settlement, n (%)

Light n ¼ 26

Medium n ¼ 151

Heavy n ¼ 119

Very Heavy n ¼ 23

F/c2 Value

P Value

R2 * 0.180§ 0.108jj N/A

N/A N/A N/A

19 (73.1%) 13 (54.2%) 7 (4.7%)

118 (78.1%) 102 (68.5%) 4 (3.4%)

111 (93.3%) 94 (81.0%) 1 (4.3%)

22 (95.7%) 18 (78.3%) 12 (3.8%)

35.00 24.24 3.74

<.001 <.001 .587

N/A

1 (4.0%)

22 (14.8%)

16 (13.6%)

3 (13.6%)

4.04

.544

N/A

0.54

.657

N/A

5.04

.411

N/A

N/A N/A

0.1 (0.6) 26 (100%)

1.0 (3.5)

0.9 (3.4)

146 (96.7%)

116 (97.5%)

0.8 (2.8) 22 (95.7%)

N/A ¼ not applicable. * Variance in 1-year socioeconomic variables that was accounted for by posttreatment PDL. † Return-to-work refers to any employment within the year after treatment discharge. ‡ Work retention refers to maintenance of employment 1 year after treatment discharge. § Odds ratios for patients in the medium, heavy, and very heavy PDLs in returning to work were 1.37 (95% confidence interval [CI] ¼ 0.51-3.68), 5.59 (95% CI ¼ 1.75-17.86), and 9.03 (95% CI ¼ 0.99-82.34), respectively, when compared to patients in the light PDL. jj Odds ratios for patients in the medium, heavy, and very heavy PDLs in retaining work were 2.00 (95% CI ¼ 0.83-4.87), 4.00 (95% CI ¼ 1.5610.26), and 3.40 (95% CI ¼ 0.93-12.45), respectively, when compared to patients in the light PDL.

those patients who had successfully returned to and had retained work 1 year after treatment discharge. The results showed that 46% of patients with a light discharge PDL, 45.2% of patients with a medium, 50% of patients with a heavy, and 43.7% of patients with a very heavy discharge PDL were working at jobs with lifting requirements that were comparable to their discharge PDLs. Most working patients who were not correctly placed (the discharge PDL was different from the work-return/retention lifting requirements) were working at jobs in which the lifting requirements were 1 level below or above their discharge PDLs. Of the 39.3% of patients who were working at jobs with lifting requirements that were lower than their discharge PDLs, many were working for a different employer in a different position, working for the same employer in a different position, completing vocational training, or self-employed. Approximately 14% of patients were working at jobs that were heavier than their discharge

PDLs. It is possible that fear avoidance and other motivational factors may have resulted in an underestimation of some patients’ maximum physical abilities at program discharge. As some of these patients re-entered the work force, they may have gained more confidence in their ability to work at a higher level than their discharge PDL. Also, some of these patients may have made additional posttreatment gains in their physical capacity through their home fitness program. Although some individual performance-based measures, such as lifting tests, have been shown to be associated with posttreatment work outcomes [12], limited evidence exists for the value of full FCEs, as represented by PDLs, to predict work outcomes. The present study found strong predictive utility for both work return after treatment completion and work retention 1 year later, based upon FCE-derived PDLs. Compared to patients with light discharge PDLs, the

Table 7 Lifting requirements for patients who were working 1 year after treatment completion, as related to their discharge physical demand levels (PDLs) (n ¼ 206) Discharge PDLs Variable Work return lifting requirements, n (%) Sedentary Light Medium Heavy Very heavy

Sedentary* n¼0

N/A N/A N/A N/A N/A

Light n ¼ 13

3 (23.1%) 6 (46.2%) 3 (23.1%) 1 (7.7%) 0%

Medium n ¼ 93

18 16 42 15 2

(19.4%) (17.2%) (45.2%) (16.1%) (2.2%)

N/A ¼ not applicable. * No patients performed at sedentary PDL at posttreatment. † Effect size (Cohen’s W): small, 0.1; medium, 0.3; large, 0.5.

Heavy n ¼ 84

3 8 24 42 7

(3.6%) (9.5%) (28.6%) (50%) (8.3%)

Very Heavy n ¼ 16

1 (6.3%) 0% 0% 8 (50%) 7 (43.7%)

c2 Value

P Value

ES

85.44

<.001

0.37†

L. Fore et al. / PM R 7 (2015) 365-375

odds ratios for patients with medium, heavy, and very heavy discharge PDLs for returning to work were 1.4, 5.6, and 9.0, respectively, and for retaining work were 2.0, 4.0, and 3.4, respectively. Increased physical functioning, as a result of functional restoration treatment, equated to increased chances of returning to, and retaining, full-duty employment, for this cohort of CDOMD patients who had previously been work disabled (76% of patients not working and 24% working with physical restrictions at treatment admission). Of course, in any study of this type, limitations can be identified. The FCE model in the present study used a standardized, evidence-based approach for assessing and quantifying function [10,28,52,54,63]. Raw data from FCE tests of range-of-motion, strength, and lifting capacity, were checked against both an external validation method (eg, normative database) and an internal validation method (ie, an effort factor) to determine each patient’s PDL. Because there is significant variation in how other treatment facilities perform FCEs and how PDLs are determined [7,23-26], the results from the present study may not generalize to other treatment facilities. In addition, the Biodex [58] equipment that was used in the FCE is relatively expensive and may not be financially viable for many other treatment facilities. Because these results were based on a CDOMD population with workers’ compensation injuries, and because the FCEs were performed in conjunction with an interdisciplinary functional restoration program (and not in isolation, outside of a treatment arena), these results may not generalize to other chronic pain populations. Nevertheless, in this cohort of CDOMD patients, the present study demonstrated that PDLs derived from FCE scores were highly responsive to functional restoration treatment. In addition, posttreatment PDLs were related to 1-year work outcomes as well as the work return/retention lifting requirements for those patients who had returned to and retained work 1 year posttreatment.

3.

4. 5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

Conclusion 16.

In conclusion, in this study, FCE scores were responsive to functional restoration treatment, and the associated posttreatment PDLs predicted work return after treatment completion and work retention 1 year later.

17.

18.

References 1. Isernhagen S. Introduction to functional capacity evaluation. In: Genovese E, Galper J, eds. Guide to the Evaluation of Functional Ability: How to Request, Interpret, and Apply Functional Capacity Evaluations. Chicago, IL: American Medical Association; 2009; 1-18. 2. Isernhagen S, Galper JS. General testing principles for functional capacity evaluations. In: Genovese E, Galper JS, eds. Guide to the

19.

20.

373

Evaluation of Functional Ability: How to Request, Interpret, and Apply Functional Capacity Evaluations. Chicago, IL: American Medical Association; 2009; 41-52. Pas L, Kuijer P, Wind H, et al. Clients’ and RTW experts’ view on the utility of FCE for the assessment of physical work ability, prognosis for work participation and advice on return to work. Int Arch Occup Environ Health 2013;87:331-338. US Department of Labor. Dictionary of Occupational Titles. 4th ed. Washington, DC: US Department of Labor; 1991. Lakke SE, Wittink H, Geertzen JH, van der Schans Cees P, Reneman MF. Factors that affect functional capacity in patients with musculoskeletal pain: A Delphi study among scientists, clinicians, and patients. Arch Phys Med Rehabil 2012;93: 446-457. Geisser ME, Robinson ME, Miller QL, Bade SM. Psychosocial factors and functional capacity evaluation among persons with chronic pain. J Occup Rehabil 2003;13:259-276. Gross DP, Battie MC. Factors influencing results of functional capacity evaluations in workers’ compensation claimants with low back pain. Phys Ther 2005;85:315-322. van Abbema R, Lakke SE, Reneman MF, et al. Factors associated with functional capacity test results in patients with non-specific chronic low back pain: A systematic review. J Occup Rehabil 2011;21:455-473. Kool J, Oesch P, de Bie R. Predictive tests for non-return to work in patients with chronic low back pain. Eur Spine J 2002;11: 258-266. Bachman S, Oesch PR, Kool JP, Persili S, Knusel O. Treatment of patients with chronic low back pain in a functional restoration program: Work related function parameters, pain parameters and the working status after 12 months. Phys Med Rehab Kuror 2003; 13:263-270. Vowles KE, Gross RT, Sorrell JT. Predicting work status following interdisciplinary treatment for chronic pain. Eur J Pain 2004;8: 351-358. Kuijer P, Gouttebarge V, Brouwer S, Reneman M, Frings-Dresen M. Are performance-based measures predictive of work participation in patients with musculoskeletal disorders? A systematic review. Int Arch Occup Environ Health 2012;85:109-123. Hazard RG, Bendix A, Fenwick JW. Disability exaggeration as a predictor of functional restoration outcomes for patients with chronic low-back pain. Spine 1991;16:1062-1067. Matheson LN, Isernhagen SJ, Hart DL. Relationships among lifting ability, grip force, and return to work. Phys Ther 2002;82: 249-256. Cheng AS, Cheng SW. The predictive validity of job-specific functional capacity evaluation on the employment status of patients with nonspecific low back pain. J Occup Environ Med 2010;52: 719-724. Cheng AS, Cheng SW. Use of job-specific functional capacity evaluation to predict the return to work of patients with a distal radius fracture. Am J Occup Ther 2011;65:445-452. Fishbain DA, Cutler RB, Rosomoff H, Khalil T, Abdel-Moty E, Steele-Rosomoff R. Validity of the dictionary of occupational titles residual functional capacity battery. Clin J Pain 1999;15: 102-110. Gouttebarge V, Kuijer PP, Wind H, van Duivenbooden C, Sluiter JK, Frings-Dresen MH. Criterion-related validity of functional capacity evaluation lifting tests on future work disability risk and return to work in the construction industry. Occup Environ Med 2009;66: 657-663. Gross DP, Battie ´ MC. The prognostic value of functional capacity evaluation in patients with chronic low back pain: Part 2: Sustained recovery. Spine (Phila Pa 1976) 2004;29:920-924. Gross DP, Battie ´ MC. Functional capacity evaluation performance does not predict sustained return to work in claimants with chronic back pain. J Occup Rehabil 2005;15:285-294.

374

Improved Functional Capacity Predicts Work Return

21. Gross DP, Battie MC. Does functional capacity evaluation predict recovery in workers’ compensation claimants with upper extremity disorders? Occup Environ Med 2006;63:404-410. 22. Reneman M, Soer R, Gross D. Developing research on performancebased functional work assessment: Report on the First International Functional Capacity Evaluation Research meeting. J Occup Rehabil 2013;23:513-515. 23. Gross DP, Haws C, Niemela ¨inen R. What is the rate of functional improvement during occupational rehabilitation in workers’ compensation claimants? J Occup Rehabil 2012;22:292-300. 24. Streibelt M, Blume C, Thren K, Reneman MF, Mueller-Fahrnow W. Value of functional capacity evaluation information in a clinical setting for predicting return to work. Arch Phys Med Rehabil 2009; 90:429-434. 25. Hart DL, Kirk M, Howar J, Mongeon S. Association between clinician-assessed lifting ability and workplace tolerance and patient self-reported pain and disability following work conditioning. Work 2007;28:111-119. 26. Cole K, Kruger M, Bates D, Steil G, Zbreski M. Physical demand levels in individuals completing a sports performance-based work conditioning/hardening program after lumbar fusion. Spine J 2009; 9:39-46. 27. Genovese E, Galper JS. Conclusions and agenda for the future. In: Genovese E, Galper JS, eds. Guide to the Evaluation of Functional Ability: How to Request, Interpret, and Apply Functional Capacity Evaluations. Chicago, IL: American Medical Association; 2009; 421-435. 28. Mayer T, Gatchel R. Functional restoration for spinal disorders: The sports medicine approach. Philadelphia: Lea & Febiger; 1988. 29. Mayer TG, Polatin PB. Tertiary nonoperative interdisciplinary programs: The functional restoration variant of the outpatient chronic pain management program. In: Mayer TG, Gatchel RJ, Polatin PB, eds. Occupational Musculoskeletal Disorders. Philadelphia, PA: Lippincott Williams & Wilkins; 2000; 639-649. 30. Dersh J, Gatchel RJ, Polatin P, Mayer T. Prevalence of psychiatric disorders in patients with chronic work-related musculoskeletal pain disability. J Occup Environ Med 2002;44:459-468. 31. Gatchel RJ, Peng YB, Peters ML, Fuchs PN, Turk DC. The biopsychosocial approach to chronic pain: Scientific advances and future directions. Psychol Bull 2007;133:581. 32. Turk DC. Biospychosocial perspective on chronic pain. In: Gatchel RJ, Turk DC, eds. Psychological Approaches to Pain Management: A Practitioner’s Handbook. New York: Guilford; 1996; 3-32. 33. Mayer TG, Gatchel RJ, Kishino N, et al. A prospective short-term study of chronic low back pain patients utilizing novel objective functional measurement. Pain 1986;25:53-68. 34. Mayer TG, Gatchel RJ, Barnes D, Mayer H, Mooney V. Progressive isoinertial lifting evaluation erratum notice. Spine 1990;15:5. 35. Curtis L, Mayer TG, Gatchel RJ. Physical progress and residual impairment quantification after functional restoration: Part III: Isokinetic and isoinertial lifting capacity. Spine 1994;19:401-404. 36. Mayer TG, Gatchel RJ, Keeley J, Mayer H, Richling D. A male incumbent worker industrial database: Part I: Lumbar spinal physical capacity. Spine 1994;19:755-761. 37. Mayer TG, Smith SS, Kondraske G, Gatchel RJ, Carmichael TW, Mooney V. Quantification of lumbar function: Part 3: Preliminary data on isokinetic torso rotation testing with myoelectric spectral analysis in normal and low-back pain subjects. Spine 1985;10: 912-920. 38. Kishino ND, Mayer TG, Gatchel RJ, et al. Quantification of lumbar function: Part 4: Isometric and isokinetic lifting simulation in normal subjects and low-back dysfunction patients. Spine 1985;10: 921-927. 39. Mayer TG, Barnes D, Kishino ND, et al. Progressive isoinertial lifting evaluation: I. A standardized protocol and normative database. Spine 1988;13:993-997.

40. Mayer TG, Barnes D, Nichols G, et al. Progressive isoinertial lifting evaluation: II. A comparison with isokinetic lifting in a disabled chronic low-back pain industrial population. Spine 1988;13: 998-1002. 41. Brady S, Mayer TG, Gatchel RJ. Physical progress and residual impairment quantification after functional restorationj part II: Isokinetic trunk strength. Spine 1994;19:395-400. 42. McGeary DD, Mayer TG, Gatchel RJ. High pain ratings predict treatment failure in chronic occupational musculoskeletal disorders. J Bone Joint Surg 2006;88:317-325. 43. Gatchel RJ, Mayer TG, Theodore BR. The pain disability questionnaire: Relationship to one-year functional and psychosocial rehabilitation outcomes. J Occup Rehabil 2006;16:72-91. 44. Jordan K, Mayer TG, Gatchel R. Should extended disability be an exclusion criterion for tertiary rehabilitation? Socioeconomic outcomes of early versus late functional restoration compensation spinal disorders. Spine 1998;23:2110-2117. 45. Howard KJ, Mayer TG, Gatchel RJ. Effects of presenteeism in chronic occupational musculoskeletal disorders: Stay at work is validated. J Occup Environ Med 2009;51:724-731. 46. Mayer TG. Quantitative physical and functional capacity assessment. In: Mayer TG, Gatchel RJ, Polatin PB, eds. Occupational Musculoskeletal Disorders: Function, Outcomes, and Evidence. Philadelphia, PA: Lippincott Williams & Wilkins; 2000; 547-560. 47. Mayer TG, Mayer E, Reese D. Lumbar musculature: Anatomy and function. In: Herkowitz H, Garfin S, Eismont F, Bell G, Balderston R, eds. Rothman-Simone: The Spine. Philadelphia, PA: WB Saunders; 2011; 80-96. 48. Beaudreuil J, Kone H, Lasbleiz S, et al. Efficacy of a functional restoration program for chronic low back pain: Prospective 1-year study. Joint Bone Spine 2010;77:435-439. 49. Hazard RG, Fenwick JW, Kalisch SM, et al. Functional restoration with behavioral support: A one-year prospective study of patients with chronic low-back pain. Spine 1989;14:157-161. 50. Kohles S, Barnes D, Gatchel RJ, Mayer TG. Improved physical performance outcomes after functional restoration treatment in patients with chronic low-back pain: Early versus recent training results. Spine 1990;15:1321-1324. 51. Mayer TG, Gatchel RJ, Mayer H, Kishino ND, Keeley J, Mooney V. A prospective two-year study of functional restoration in industrial low back injury. JAMA 1987;258:1763-1767. 52. Mayer TG. Functional restoration of patients with chronic spinal pain. In: Fardon D, Garfin S, eds. AAOS Spine Orthopedic Knowledge Update. 2nd ed. Rosemont, IL: AAOS Press; 2002; 229-238. 53. Patrick LE, Altmaier EM, Found EM. Long-term outcomes in multidisciplinary treatment of chronic low back pain: Results of a 13-year follow-up. Spine (Phila Pa 1976) 2004;29:850-855. 54. Roche G, Ponthieux A, Parot-Shinkel E, et al. Comparison of a functional restoration program with active individual physical therapy for patients with chronic low back pain: A randomized controlled trial. Arch Phys Med Rehabil 2007;88: 1229-1235. 55. Beck AT, Ward CH, Mendelson M, Mock J, Erbaugh J. An inventory for measuring depression. Arch Gen Psychiatry 1961;4: 561. 56. Anagnostis C, Gatchel RJ, Mayer TG. The pain disability questionnaire: A new psychometrically sound measure for chronic musculoskeletal disorders. Spine 2004;29:2290-2302. 57. Mayer TG, Prescott M, Gatchel RJ. Objective outcomes evaluation: Methods and evidence. In: Mayer TG, Gatchel RJ, Polatin PB, eds. Occupational Musculoskeletal Disorders: Function, Outcomes, and Evidence. Philadelphia, PA: Lippincott Williams & Wilkins; 2000; 651-667. 58. Biodex Medical Systems. Updated 2014. Available at: http://www. biodex.com/physical-medicine/products. Accessed April 3, 2014.

L. Fore et al. / PM R 7 (2015) 365-375 59. Smith SS, Mayer TG, Gatchel RJ, BeckerR TJ. Quantification of lumbar function: Part 1: Isometric and multispeed isokinetic trunk strength measures in sagittal and axial planes in normal subjects. Spine 1985;10:757-764. 60. Mayer TG, Smith SS, Keeley J, Mooney V. Quantification of lumbar function: Part 2: Sagittal plane trunk strength in chronic low-back pain patients. Spine 1985;10:765-772. 61. Mayer T, Gatchel R, Betancur J, Bovasso E. Trunk muscle endurance measurement: Isometric contrasted to isokinetic testing in normal subjects. Spine 1995;20:920-925. 62. Mayer TG, Gatchel RJ, Keeley J, Mayer H. Optimal spinal strength normalization factors among male railroad workers. Spine 1993; 18:239-244.

375

63. Fore L, Keeley J, Mayer TG. Functional capacity evaluation for patients with chronic pain. In: Genovese E, Galper JS, eds. Guide to the Evaluation of Functional Ability: How to Request, Interpret, and Apply Functional Capacity Evaluations. Chicago, IL: American Medical Association; 2009; 291-312.

This journal-based CME activity is designated for 1.0 AMA PRA Category 1 Credit and can be completed online at www.me.aapmr.org. This activity is FREE to AAPM&R members and available to nonmembers for a nominal fee. For assistance with claiming CME for this activity, please contact (847) 737-6000.

Disclosure L.F. PRIDE Research Foundation, Dallas, TX Disclosure: nothing to disclose Y.P. PRIDE Research Foundation, Dallas, TX Disclosure: nothing to disclose

R.J.G. Department of Psychology, University of Texas at Arlington, Arlington, TX Disclosures outside this publication: consultancy, PRIDE (money to author); grants/grants pending, NIH and NSF (money to author); royalties, Guilford Press, Springer, APA Press (money to author); other, endowments (Nancy P. & John G. Penson Endowed Professorship in Clinical Health Psychology), Palladian Health (scientific advisory board) (money to author)

R.N. PRIDE Research Foundation, Dallas, TX Disclosure: nothing to disclose

Peer reviewers and all others who control content have no relevant financial relationships to disclose.

S.A. PRIDE Research Foundation, Dallas, TX Disclosure: nothing to disclose

Submitted for publication December 20, 2013; accepted September 26, 2014.

T.G.M. Department of Orthopedic Surgery, University of Texas Southwestern Medical Center at Dallas, 5701 Maple Ave. #100, Dallas, TX 75235. Address correspondence to: T.G.M.; e-mail: [email protected] Disclosure: nothing to disclose

CME Question Which is the best predictor of work return and work retention after Functional Restoration Rehabilitation? a. b. c. d.

discharge physical demand level depressive symptoms perceived disability length of disability

Answer online at me.aapmr.org