A Randomized Clinical Trial of Targeted Cognitive Behavioral Treatment to Reduce Catastrophizing in Chronic Headache Sufferers

The Journal of Pain, Vol 8, No 12 (December), 2007: pp 938-949 Available online at www.sciencedirect.com

A Randomized Clinical Trial of Targeted Cognitive Behavioral Treatment to Reduce Catastrophizing in Chronic Headache Sufferers Beverly E. Thorn,* Laura B. Pence,* L. Charles Ward,† Gary Kilgo,‡ Kristi L. Clements,* Tony H. Cross,* Amber M. Davis,* and Patricia W. Tsui* *Psychology Department, The University of Alabama, Tuscaloosa, Alabama. † Department of Veterans Affairs Medical Center, Tuscaloosa, Alabama. ‡ The Kilgo Headache Clinic, Northport, Alabama.

Abstract: This randomized clinical trial (RCT) examined the efficacy of a cognitive-behavioral treatment (CBT) specifically targeted toward reducing pain catastrophizing for persons with chronic headache. Immediate treatment groups were compared with wait-list control groups. Differential treatment gains based on the order of presentation of 2 components of CBT (cognitive restructuring and cognitive/behavioral coping) and the role of catastrophizing in treatment outcome were examined. Thirty-four participants enrolled in a 10-week group treatment and 11 completed a wait-list self-monitoring period. Participants reported significant reductions in catastrophizing and anxiety and increased self-efficacy compared with wait-list control subjects, and these were maintained at follow-up. Although we did not find overall differences in the reduction of headache frequency or intensity compared with wait-list control subjects, calculation of clinical significance on headache indicators suggest that approximately 50% of treated participants showed meaningful changes in headache indices as well. Order of treatment modules was not related to gains during treatment or at follow-up; however, almost all changes occurred during the second half of treatment, suggesting that duration of treatment participation is important. Perspective: Cognitive-behavioral treatment targeting reduction of catastrophizing for chronic headache pain reduced negative cognitive and affective variables associated with recurrent headache, increased headache management self-efficacy, and in half of the participants, produced clinically meaningful reductions in headache indicators. Length of treatment is an important factor to consider when providing CBT for chronic pain. © 2007 by the American Pain Society Key words: Headache, pain, cognitive behavioral therapy, catastrophizing, randomized clinical trial, psychosocial.

T

reatment outcome studies indicate that cognitivebehavioral therapy (CBT) is an effective component of multidisciplinary treatment for adults with chronic pain,24,31,43 including headache pain. Patients with headache who undergo CBT have reported reductions in headache frequency, intensity, duration, and Received April 9, 2007; Revised June 11, 2007; Accepted June 25, 2007. Supported in part by National Institute on Neurological Disorders and Stroke grant R-15 NS 42323, awarded to Dr. Thorn. Address reprint requests to Dr. B.E. Thorn, Department of Psychology, PO Box 870348, The University of Alabama, Tuscaloosa, AL 35487-0348. E-mail: [email protected] 1526-5900/$32.00 © 2007 by the American Pain Society doi:10.1016/j.jpain.2007.06.010

938

medication use and improvements in quality of life.14,19,25 Meta-analyses of behavioral headache treatments have reported a mean percentage reduction in headache frequency of about 30% to 50% for migraine and tension-type headaches before to after treatment.11,30 The term CBT implies a single treatment approach. However, techniques classified as components of CBT include but are not limited to relaxation, biofeedback, stress management, training in pain coping strategies, and cognitive restructuring for dysfunctional thinking. There are few published studies comparing the utility of specific components of this relatively complex intervention. Holroyd and Andrasik13 used an additive design to

ORIGINAL REPORT/Thorn et al compare cognitive therapy with cognitive therapy plus relaxation for tension-type headache. Both “active” treatments produced a substantial reduction in headache symptoms relative to a symptom-monitoring control group. Headaches were also reduced in a discussiononly comparison group, raising questions about the mechanisms associated with treatment efficacy. However, the discussion-only group was instructed to monitor their cognitive responses to stress-eliciting situations, which is 1 component of cognitive therapy.39 Investigators have suggested that it may be more important to reduce negative pain-related thinking than to increase one’s coping repertoire,10,30,41 although this is not empirically supported. The critical components for treatment success, including the order of treatment components, are not known. Additionally, it is not understood why CBT works better for some patients than others. An important psychological predictor of adjustment to pain is pain catastrophizing, an exaggerated negative mental set brought to bear during the experience of pain.37 Changes in catastrophizing are predictive of treatment outcome in pain populations other than headache pain,4,15,38 and mediate treatment outcomes such as reductions in pain intensity.31,33 It has been suggested that changes in cognitive reactions to headache may also mediate headache treatment effectiveness.26 Moreover, it has been hypothesized that teaching adaptive coping strategies might be less effective for those patients who are high in dysfunctional thinking about pain.10 Researchers have demonstrated that frequency of coping is associated with pain reduction for noncatastrophizers but not for catastrophizers.32,34 Thus, catastrophizers might benefit more from focusing on the reduction of catastrophizing through cognitive restructuring. Both migraineurs and tension-type headache sufferers have been shown to endorse more catastrophic thoughts than headache-free control subjects when dealing with painful events.6,12,44 Researchers exploring cognitive-behavioral treatments not specifically targeting catastrophizing have nevertheless reported an association between reductions in headache intensity and changes in cognitive appraisals.23,26 There are no published treatment outcome studies specifically targeting the reduction of catastrophizing in the headache literature. The purpose of this study was to conduct a randomized clinical trial (RCT) to explore the efficacy of CBT for headache by comparing immediate treatment and wait-list control groups. Another purpose was to examine differential gains based on the order of presentation of the 2 major components of CBT: 1) Cognitive restructuring, focused on the reduction of pain-specific dysfunctional cognitions, primarily pain catastrophizing; and 2) coping, focused on teaching cognitive and behavioral coping strategies. We predicted that, regardless of treatment order, participants receiving treatment would report greater treatment gains than wait-list control subjects. Further, we predicted that participants receiving cognitive restructuring first would report greater

939 treatment gains than participants receiving cognitive coping first. A secondary aim was to examine the effect of catastrophizing on treatment outcome. We predicted that, for high catastrophizers, treatment would be more effective when cognitive restructuring was presented first because this would allow catastrophizers to be more responsive to coping strategy training.

Materials and Methods Settings and Participants This study was approved by the institutional review board at The University of Alabama, where the data were collected. All participants provided written informed consent. Participants were recruited through a variety of sources: Patients seeking treatment for headache from a local neurologist at the Kilgo Headache Clinic, pamphlets placed in other local psychology clinics or physician’s offices, and newspaper advertisements. Study eligibility criteria included the following: (1) At least 3 pain days per month due to migraine and/or tension-type headaches that meet diagnostic criteria according to the Headache Classification Committee of The International Headache Society40; (2) recent evaluation (within 6 months) of headaches by a physician; (3) no history of seizure or facial neuralgia, as these conditions might preclude the accurate diagnosis of headache; (4) age of 19 years or older; (5) no significant cognitive impairment, evidenced by a score of less than 24 on the Mini-Mental Status Exam (MMSE)7; (6) reading ability sufficient to comprehend self-monitoring forms; (7) if currently using psychotropic or headache medications, use of these medications must have begun at least 4 weeks before treatment; and (8) no history of schizophrenia, bipolar affective disorder, or current substance abuse as these conditions could result in psychiatric emergency during treatment. Of approximately 150 people who were contacted to participate in the study, 40 enrolled (about 27%; Fig 1). Thirty-four attended at least 1 CBT session, and 31 completed the treatment (1 person was excluded from diary analysis due to low diary completion rates [21% of days]). The most common reason provided for not enrolling in the treatment was the time commitment involved in participating in a 10-week group. We could not address potential differences between those who participated in the groups and those who did not enroll because this information is not available.

Procedures Participants were screened for eligibility via telephone interviews. Those meeting eligibility criteria were invited to the clinic to complete the informed consent process, an initial headache history interview (which provided information relevant to making a specific headache diagnosis based on the criteria of the International Headache Society (International Classification of Headache Disorders-II [ICHD-II]; IHS),40 and the baseline assessment

940

Targeted Treatment to Reduce Catastrophizing

Figure 1. Participant flow through the RCT. a, Follow-up rates based on randomly assigned participants (total n ⫽ 34). b, Eight participants were not given the opportunity to participate in the 6-month follow-up. c, Intention to treat analyses were used to incorporate data from treatment noncompleters.

package. They also received instructions on daily selfmonitoring of headache pain. After participants completed the baseline assessment package, they began a daily self-monitoring period until treatment began. To control for the effects of pre and post-treatment assessment, symptom self-monitoring, and spontaneous remission of symptoms, some participants were assigned to a wait-list self-monitoring control group (delayed treatment condition). We chose a delayed treatment condition rather than a placebo control because there is sufficient evidence that cognitive-behavioral treatment for headache is efficacious,30 and, based on the Declaration of Helsinki,46,47 placebo trials should not be undertaken when an efficacious therapy is available. Furthermore, we were comparing the order of presentation of treatment modules in an attempt to explain the active elements of treatment, and the 2 treatment orders were randomized. Due to the relatively small number of par-

ticipants available at a single time, it was not feasible to conduct all groups simultaneously. Rather, all participants were instructed to begin self-monitoring immediately after completing the initial interview. The wait-list group consisted of participants who completed at least 9 weeks of self-monitoring before beginning a treatment group; thus, assignment to wait-list versus immediate treatment condition was based on when participants became available to participate in a group. All participants in the wait-list condition were contacted by telephone approximately once per week during the self-monitoring period. When a sufficient number of participants became available, a treatment group was assembled. All groups received 1 of 2 active treatments differing only in order of presentation of 2 treatment modules (cognitive restructuring and cognitive/behavioral coping) and all participants were told they were receiving a real treatment. The order of treatment modules to be delivered to

ORIGINAL REPORT/Thorn et al

941

Figure 2. Order of presentation of treatment modules and objectives of each session.

each available group was determined randomly by a coin toss. Only 1 of the 2 treatment groups was conducted at a single time. Participants completed a battery of questionnaires at baseline, immediate pretreatment, midtreatment (after 5 sessions), post-treatment (after 10 sessions), 6 months post-treatment, and 12 months post-treatment. Participants completed baseline and treatment assessments at the clinic, whereas follow-up assessments were completed in the clinic or by mail. Participants were paid $25 after completion of the midtreatment assessment, the post-treatment assessment, and each follow-up assessment; thus, participants were eligible to earn up to $100 for completion of all assessments.

Intervention Protocols Regardless of the treatment condition, the treatment was delivered in a group format (5– 8 individuals) in 10weekly sessions (1.5 hours each) according to a treatment manual. The cognitive components of the treatment manual are published in Thorn.40 The exact treatment manual is available upon request from the first author. Groups were co-led by the Principal Investigator, a licensed clinical psychologist who had prior experience delivering CBT to patients with chronic pain, and an advanced graduate student in clinical psychology. Each session generally included the following: 1) Completing review questions; 2) review and discussion of material from the previous session; 3) instruction, discussion, and practice of new material; 4) presentation of homework assignment; and 5) completion of review questions regarding the material from that session.

All participants received a patient treatment manual including outlines of each session and homework assignment. Outlines and assignments relevant to the current week were passed out each session, so participants did not have future outlines available in advance. Each group, regardless of treatment order, received an initial session with the purpose of introducing the stress-pain connection and the cognitive model (thoughts influence feelings, behavior, and physiology). Next, half of the participants received the 4 cognitive restructuring modules followed by the 4 cognitive/behavioral coping modules and the other half received the opposite treatment order. Each group also received a closing session designed to summarize, integrate, and encourage maintenance of the new concepts and skills. See Fig 2 for a diagram of treatment order and a more detailed explanation of the content of each module. Participants were encouraged to attend all sessions. However, individual make-up sessions were provided when necessary. We found that individual make-up sessions allowed members to stay on track with treatment and to still thoroughly learn the information provided, even though the added benefit of group interaction was lost. Eight patients had 100% attendance in the group sessions, 15 had 1 make-up session, and 8 had 2 make-up sessions. Our make-up policy also helped us maintain a low group dropout rate (n ⫽ 3, or 8.8%).

Measures Pain. Pain due to headaches was assessed daily using a headache diary adapted from Blanchard and An-

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Targeted Treatment to Reduce Catastrophizing 3

drasik. Most participants completed diaries using a notebook, but, when possible, participants used an online pain diary to increase consistency and accuracy in record keeping. Participants rated the frequency, intensity, and unpleasantness of headache pain one time each day. Pain severity and unpleasantness were rated on an 11-point Likert scale ranging from 0 (“no pain/no unpleasantness”) to 10 (“pain/unpleasantness as bad as it can be”). Headache frequency, peak headache rating, mean pain intensity, and mean pain unpleasantness were calculated for each week of record keeping. Pain unpleasantness ratings were considered to be a measure of distress associated with the headache episode. Medication. As part of their daily diary, patients were requested to keep a record of the medication taken to prevent or relieve headache. They were asked to indicate the name of the medication taken, the dose, and the time taken each day in an effort to relieve headache. This information was kept throughout the baseline and treatment period. Catastrophizing. Catastrophizing was assessed using the Pain Catastrophizing Scale (PCS).34 The PCS is 13-item self-report inventory designed to assess the extent to which persons use a catastrophic thinking approach to pain stimuli. Patients are instructed to reflect on a painful experience and to indicate the extent to which he or she thought about each statement using a 5-point Likert scale ranging from 0 (“not at all”) to 4 (“all the time”). Total catastrophizing scores range from 0 –52. Research suggests that patients obtaining a total score above 38 (the 80th percentile) are particularly prone to adjustment difficulties and poor progression through pain rehabilitation.36 The PCS has demonstrated high internal consistency (Cronbach’s ␣ ⫽ 0.91), and high test-retest reliability over a 6 week period (r ⫽ 0.75).34,45 Construct validity of the PCS has been demonstrated both in experimental cold pressor studies34 and in clinical patient samples undergoing painful procedures.34,35 Depression. Symptoms of depression were assessed with the Beck Depression Inventory- Second Edition (BDIII).2 The BDI-II is a 21-item self-report measure of depressive symptoms. Each item consists of 4 choices (rated 0 to 3) representing the level of severity of the symptom described. Total scores range from 0 – 63, with higher scores reflecting greater symptom severity. The BDI-II is one of the most widely used instruments for assessing depression in adults. Across a variety of studies, the BDI-II has exhibited internal consistency (range Cronbach’s ␣ ⫽ .92) and test-retest reliability over a 1-week period (r ⫽ .93).2 Anxiety. Symptoms of generalized anxiety were assessed with the Beck Anxiety Inventory (BAI).1 The BAI is a 21-item self-report inventory for measuring the severity of anxiety symptoms. Each item consists of 4 choices ranging from “not at all” to “severely” on which patients rate how much they are bothered by various anxiety related symptoms. Total scores range from 0 – 63, with higher scores reflecting greater endorsement of anxiety symptom severity. The BAI has demonstrated excellent internal consistency (Cronbach’s ␣ ⫽ .93), adequate test-

retest reliability (r ⫽ .67), and convergent and discriminant validity.9 Pain specific anxiety. The Pain Anxiety Symptom Scale (PASS) was used as a measure of pain-related anxiety and fear.22 Four components of pain related anxiety are assessed by the 40-item questionnaire: fearful appraisal of pain (eg, “When I feel pain, I am afraid something terrible may happen.”), cognitive anxiety (eg, “During painful episodes, it is difficult for me to think of anything besides the pain.”), physiological anxiety (eg, “Pain seems to cause my heart to pound or race.”), and escape-avoidance behavior (eg, “I avoid important activities when I hurt.”). Patients indicate the extent to which each item applies to them on a 7-point Likert scale ranging from 0 (“never”) to 6 (“always”). The PASS has exhibited internal consistency for each subscale and the total score (range Cronbach’s ␣ ⫽ .81–.94). The authors also suggest that the PASS has demonstrated adequate construct and concurrent validity.22 Self-efficacy. The Headache Management Self-Efficacy Scale (HMSE)8 was used to assess the patients’ confidence in their ability to prevent the onset of headaches and to manage headache pain. Twenty-five statements related to headache management are rated on a 7-point Likert scale ranging from 1 (“strongly disagree”) to 7 (“strongly agree”). Ratings are summed to produce a total score, with higher scores reflecting greater perceived self-efficacy. The HMSE has demonstrated internal consistency (Cronbach’s ␣ ⫽ .90) and construct validity8; however, no other psychometric indicators such as test-retest reliability are available. Demographics. Participants provided demographic information including age, race, income, years of education, and marital status. Headache diagnostic subgroup categories were also used in demographic analyses.

Treatment Implementation, Receipt, and Enactment Treatment implementation was monitored by the principal investigator, who conducted or observed and supervised all CBT sessions. She monitored the treatment sessions to ensure that the treatment manual was adhered to and that quality criteria were met. Treatment receipt and enactment was assessed by examining review questions before and after each session (eg, “List the main point of last week’s session.”) and homework assignment completion. At the end of each session, participants were able to successfully identify the main point of that session and at least 1 way in which they could think or act differently in the coming week based on the new material learned 99.7% of the time. At the beginning of each session, participants were able to successfully identify the main point of the previous session and a way they acted or thought differently after the session 95.7% of the time. The common error was to report a main idea and way to act differently from a previous session other than the most recent session. Participants completed 92.7% of homework assignments.

ORIGINAL REPORT/Thorn et al

Statistical Analyses Analyses were conducted to assess change during treatment in self-report outcome questionnaires (PCS, BDI-II, BAI, PASS, and HMSE) and daily diary headache pain ratings. For the questionnaire data, change scores (post-treatment minus pretreatment) were computed. Negative change scores indicate improvement during treatment for the PCS, BDI-II, BAI, and PASS, and positive change scores indicate improvement for the HMSE. For pain diary data, change was assessed by computing the slopes of the linear regression for the prediction of diary ratings (headache frequency, weekly peak headache intensity, weekly average pain intensity, and weekly average pain distress) for the self-monitoring period and for the treatment period. The linear regression lines were based on 9 data points, which were divided in equal 1 week increments. The procedure, which is described by Kraemer and Thiemann,18 produces scores (slopes) that are equivalent in meaning and magnitude to change scores that are based only on pretest and pretreatment scores (or pain ratings at weeks 1 and 10). However, power may be improved by using all of the available data when there are 5 or more measurement occasions.21 Intent-to-treat analyses were conducted by having the last observation carried forward (LOCF) for the questionnaire outcome data when data were missing at the end of treatment (due to dropout or missing data for completers). LOCF was also used for diary ratings to keep procedures comparable to those used with the questionnaire data and to prevent early termination data from unduly influencing slopes. For example, when the diary ratings were missing for the 10th week during the treatment period, the diary ratings from the ninth week were substituted for the missing data. For the questionnaire data, pretreatment data was carried forward through the midtreatment and post-treatment assessments for the 3 noncompleters. Out of 306 total data points for the diary, 20 were carried forward from the last week completed for the 3 noncompleters and 14 were carried forward from the previous week for treatment completers with occasional missing data. To test whether changes in outcome measures (selfreport questionnaire data, diary ratings) during treatment were significant for the treatment package as a whole, regardless of treatment order, and to test whether changes during treatment were dependent on the order of presentation of treatment modules, a multivariate analysis of variance (MANOVA) was used with treatment order as the independent variable. Additional analyses related to the importance of the order of treatment were also conducted. Specifically, MANOVAs were used to test the significance of change from baseline to pretreatment, pre to midtreatment, and mid to posttreatment and to test for differences in change scores between the first and second half of treatment. Similar analyses were conducted on the follow-up data. Data used in the analyses were from the 12-month follow-up, except for 3 cases in which 6-month data substituted for the 12-month data because those partici-

943 pants elected not to complete the 12-month follow-up. To test the significance of change scores (follow-up minus pretreatment), and to test whether changes from pretreatment to follow-up were dependent on the order of presentation of treatment modules, a MANOVA with treatment order as the independent variable was conducted. To test whether changes for the immediate treatment group were significantly different from the wait-list control, a MANOVA was conducted with condition (immediate treatment vs wait-list control) as the independent variable and change scores (pretreatment minus baseline for the wait-list group and post-treatment minus pretreatment for the immediate treatment group) as the dependent variable. To examine the relation between catastrophizing and treatment gains (treatment change scores), an interaction analysis was conducted to test whether the importance of treatment order was dependent on pretreatment catastrophizing levels, with treatment order, pretreatment PCS scores, and the treatment order x PCS score interaction as independent variables.

Results Sample Characteristics, Session Attendance, and Follow-up Response Headache diagnosis was determined for each participant at entry into the study based upon the criteria of the International Headache Society (IHS).40 Seventeen participants (50%) met criteria for migraine with aura or migraine without aura, 4 participants (14.7%) met criteria for tensiontype headache (TTH; infrequent, frequent, or chronic), and 12 (35.3%) met criteria for both migraine and tension-type headache. There were no differences in the dependent variables at entry into the study based on headache diagnosis except in headache management self-efficacy, F ⫽ 6.53, P ⬍ .01. Participants with mixed migraine and TTH reported the highest headache management self-efficacy (M ⫽ 131.13, SD ⫽ 16.91), followed by those with migraine (M ⫽ 110.86, SD ⫽ 22.99), and TTH (M ⫽ 93.75, SD ⫽ 17.39). Participants with TTH headache reported mean levels of self-efficacy 1 standard deviation below the sample mean, and just less than 1 standard deviations below the mean reported in the validation study for the HMSE (M ⫽ 110.29, SD ⫽ 20.90).8 Although we screened for medication overuse headache based on IHS criterion, we did not automatically exclude participants based on this criterion. The sample included one participant who met criterion for “probable medication overuse headache” and one participant who approached, but did not meet criterion, even for “probable” medication overuse. At baseline, 55.9% of participants reported using abortive medications (primarily selective 5-hydroxytryptamine1 receptor subtype agonists, tryptans), 58.8% reported using nonopioid analgesics, and 35.3% reported using opioid or combination opioid/nonopioid analgesics.

944 Table 1.

Targeted Treatment to Reduce Catastrophizing

Demographic Characteristics of Group Members TOTAL SAMPLE

Headache diagnosis (%) Migraine (with or without aura) Tension-type headache Mixed Age (years) Mean (SD) Gender (%) Female Male Race (%) White Black Marital status (%) Married Unmarried (single, widowed, divorced) Years of education Mean (SD) Income (yearly) (%) 0 to 24,999 25,000 to 49,999 50,000 to 100,000 100,000⫹ Employment status (%) Employed or student Unemployed

GROUP 1: COGNITIVE RESTRUCTURING-COGNITIVE COPING

GROUP 2: COGNITIVE COPING-COGNITIVE RESTRUCTURING

P VALUE NS

17 (50) 5 (14.7) 12 (35.3)

10 (66.7) 2 (13.3) 3 (20.0)

7 (36.8) 3 (15.8) 9 (47.4) NS

42.71 (13.18)

41.71 (12.62)

43.5 (13.9)

82.4 17.6

86.7 13.3

78.9 21.1

82.4 17.6

86.7 13.3

78.9 21.1

61.8 35.3 16.59 (2.55)

53.3 40.0 16.38 (2.39)

68.4 31.3 16.74 (2.70)

17.6 26.5 29.4 17.6

20.0 26.7 33.3 6.7

15.8 26.3 26.3 26.3

76.5 20.6

93.3 0.0

63.2 36.8

NS

NS

NS

NS NS

.01

NOTE. Some percentages do not total 100% due to missing data.

The 2 treatment groups (ie, based on treatment order) did not differ on the sociodemographic characteristics examined, except that there was a larger percentage of participants in group 2 (cognitive coping first) who were not employed (Table 1). Participants in the delayed treatment condition did not differ from participants in the immediate treatment conditions on diagnosis, sociodemographic characteristics, or the dependent variables assessed at baseline (catastrophizing, depression, anxiety, pain specific anxiety, and headache management selfefficacy) (for all t tests and ␹2 tests, P ⬎ .05). The large percentage of women in this study is consistent with research suggesting that women are twice as likely as men to seek treatment for headache.20 Many participants reported multiple sources of pain in addition to headaches (eg, fibromyalgia, low back pain), although data are not available on the frequencies of specific comorbid conditions. Of the total sample enrolled (n ⫽ 40), 6 participants (15%) were never assigned to a treatment group because they decided against treatment or failed to appear after initial enrollment. Of the 34 ultimately assigned to a treatment group, 11 were considered the wait-list control group and 23 were considered the immediate treatment group. Regardless of assignment to immediate treatment or wait-list control, 31 participants (77.5%) completed treatment by attending all sessions (either group session or make-up) and the 3 (8.8%) who dropped out of treatment attended 3 or 4 sessions. Two of the 3 dropouts were in immediate treatment groups,

and 1 dropout was in a delayed treatment group. Fig 1 provides information regarding completion of intervention and follow-up assessments. The 2 treatment groups (ie, based on treatment order) did not differ significantly in the number of participants completing at least 1 follow-up (␹2 ⫽ .717, P ⬎ .05).

Overall Treatment Efficacy Means and standard deviations of outcome variables as measured at each time point are presented in Table 2. A multivariate analysis of variance indicated that changes reported by those participants in the immediate treatment condition were significantly greater than those reported by participants in the wait-list condition [F(9, 22) ⫽ 2.813, P ⬍ .05]. Univariate tests indicated significant differences in change scores between the immediate treatment and wait-list groups for the PCS, F(1,30) ⫽ 4.399, P ⫽ .044, d ⫽ ⫺.52, BAI, F(1,30) ⫽ 6.472, P ⫽ .016, d ⫽ ⫺.80, and HMSE, F(1,30) ⫽ 19.096, P ⬍ .001, d ⫽ 1.26, but not for the BDI-II, F(1,30) ⫽ 0.172, P ⬎ .05, d ⫽ ⫺.16, PASS, F(1,30) ⫽ 2.105, P ⬎ .05, d ⫽ ⫺.32, weekly headache frequency, F(1,30) ⫽ 1.597, P ⬎ .05, d ⫽ ⫺.48, peak headache intensity, F(1,30) ⫽ 0.396, P ⬎ .05, d ⫽ ⫺.20, average weekly headache intensity, F(1,30) ⫽ 0.186, P ⬎ .05, d ⫽ ⫺.17, or average weekly headache distress, F(1,30) ⫽ 0.129, P ⬎ .05, d ⫽ ⫺.12. Effect sizes for differences between immediate treatment and wait-list groups were large for self-efficacy and anxiety, and medium for catastrophizing. Although there was insufficient power to detect a statistically significant effect, there was a medium effect size for the

ORIGINAL REPORT/Thorn et al Table 2.

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Means and Standard Deviations of Outcome Variables at Each Assessment BASELINE

PCS BDI-II BAI PASS HMSE Frequency* Average intensity Peak intensity Average unpleasantness

PRETREATMENT

MIDTREATMENT

POST-TREATMENT

6-MONTH FOLLOW-UP

12 MONTH FOLLOW-UP

M

SD

M

SD

M

SD

M

SD

M

SD

M

SD

16.76 10.23 10.43 76.21 117.58 – – – –

10.04 7.05 7.55 32.84 20.42 – – – –

16.53 9.68 10.76 74.60 115.40 3.45 2.32 5.83 2.00

8.53 6.93 8.77 31.79 24.19 1.82 1.51 1.94 1.37

15.26 10.09 11.09 70.69 126.21 – – – –

8.27 7.21 7.42 29.54 21.27 – – – –

12.28 7.49 7.42 65.83 138.02 3.19 1.84 4.72 1.54

7.41 5.66 5.75 27.14 23.52 2.05 1.34 2.00 1.18

11.72 6.08 7.09 77.06 142.46 – – – –

8.89 7.60 8.55 30.11 21.40 – – – –

9.60 6.85 7.70 54.79 142.41 – – – –

6.29 6.64 7.78 28.82 20.26 – – – –

*Headache indices were calculated for the last 2 weeks preceding treatment (pretreatment) and the last 2 weeks of treatment (post-treatment).

difference between the immediate and wait-list groups for headache frequency. Regardless of treatment order, change during treatment was significant [F(9, 22) ⫽ 5.836, P ⬍ .001]. The results from univariate analyses of variance are summa-

Table 3.

rized in Table 3. Changes during treatment were significant in the hypothesized directions for all of the measures, except that there were only nonsignificant trends for weekly average pain intensity and unpleasantness. Effect sizes were small for headache frequency and peak

Tests of Change Scores During Treatment at Post-Treatment and Follow-up CHANGES

FROM

GROUP* MEAN CHANGE PCS

BDI-II

BAI

PASS

HMSE

Headache frequency‡

Peak intensity

Average weekly pain intensity

Average weekly pain unpleasantness

1 2 Total 1 2 Total 1 2 Total 1 2 Total 1 2 Total 1 2 Total 1 2 Total 1 2 Total 1 2 Total

⫺4.73 ⫺3.59 ⫺4.24 ⫺2.53 ⫺2.39 ⫺2.45 ⫺3.133 ⫺3.51 ⫺3.34 ⫺13.96 ⫺4.67 ⫺8.76 24.18 21.39 22.62 ⫺.07 ⫺.14 ⫺.10 ⫺.94 ⫺1.13 ⫺1.04 ⫺4.32 ⫺3.24 ⫺3.73 ⫺3.65 ⫺2.30 ⫺2.91

PRE

SD

TO

POST-TREATMENT

F(1,30)

d†

CHANGES P

8.09 6.62 7.91 19.641 ⫺.54 .001 3.89 5.44 4.73 7.989 ⫺.52 .008 4.34 8.60 6.95 8.272 ⫺.48 .007 21.59 24.82 23.58 10.51 ⫺.37 .003 21.16 18.57 19.49 44.27 1.16 ⬍ .001 .30 .23 0.26 4.101 ⫺.38 .052 3.15 2.67 2.85 4.49 ⫺.36 .043 16.09 7.91 12.12 2.732 ⫺.31 .109 14.28 9.86 11.89 2.00 ⫺.25 .167

FROM

MEAN CHANGE ⫺10.50 ⫺4.64 ⫺6.77 ⫺1.75 ⫺1.73 ⫺1.73 ⫺2.00 ⫺3.64 ⫺3.05 ⫺22.85 ⫺14.99 ⫺17.85 26.71 27.50 27.21 – – – – – – – – – – – –

PRETREATMENT SD

F(1,15)

TO

FOLLOW-UP d

P

9.74 7.48 8.64 16.782 ⫺.78 .001 3.45 7.30 6.07 1.588 ⫺.28 .22 4.31 7.89 6.74 3.452 ⫺.45 .078 25.08 34.17 30.79 7.445 ⫺.58 .01 17.40 22.43 20.31 34.547 1.34 ⬍ .001 – – – – – – – – – – – – – – – – – – – – – – – –

*Group 1 ⫽ Cognitive restructuring followed by cognitive coping, group 2 ⫽ cognitive coping followed by cognitive restructuring. †d represents the effect size for changes during treatment for the treatment group. ‡Values reported for pain data (headache frequency, peak intensity, average weekly pain intensity, and average weekly pain unpleasantness) are given as the slope of the change over time rather than change in raw scores.

946 intensity, medium for catastrophizing, depression, and anxiety, and very large for headache management selfefficacy. At follow-up, the multivariate effect for change was significant [F(5, 16) ⫽ 8.233, P ⫽ .001]. Univariate analyses are summarized in Table 3. Changes at follow-up in relation to pretreatment were significant for the PCS, PASS, and the HMSE, and effect sizes were large for PCS and HMSE. Effect sizes of change at follow-up were medium for the PASS and the BAI and small for the BDI-II. But, as during treatment, the effects for the BAI and BDI-II were not significant. No measure of pain intensity or frequency was taken at follow-up.

Clinical Significance of Change Of the 31 participants who completed treatment, 27 provided sufficient diary data to calculate clinical significance for changes in headache outcome variables as well as medication use. (Four of the 31 participants did not provide complete diary responses for the last 2 weeks of treatment, and they were therefore not included in the following analyses.) The percentage of patients deemed “clinically improved” based on headache frequency was determined per American Headache Society’s Behavioral Clinical Trials Workgroup Guideline for Trials of Behavioral Treatments for Recurrent Headache.29 That is, those with a 50% or greater reduction in headache frequency from pre to post-treatment were considered treatment “responders,” those with a 25% to 49% change in headache frequency from pre to post-treatment were considered “modest responders” or “somewhat” improved, and those exhibiting less than 25% change in headache frequency were considered treatment “nonresponders” or “not improved.” Eleven treatment completers (40.7%) were considered at least modest responders (29.6% responders, 11.1% modest responders) based on changes in headache frequency. The number of participants considered at least a modest responders in the immediate treatment groups were significantly greater than the number of participants considered at least modest responders in the wait-list control group during their waitlist period [␹2 ⫽ 4.41, P ⫽ .042]. There were no differences found between those considered at least modest responders based on headache frequency and those considered nonresponders on sociodemographic characteristics, headache diagnosis, pretreatment headache frequency, intensity, peak pain or unpleasantness, pretreatment scores on the dependent variables (catastrophizing, depression, anxiety, pain specific anxiety, and headache management self-efficacy scores), or use of abortive, nonopioid, or opioid medications at baseline (for all t tests and ␹2 tests, P ⬎ .05). Percent change was also calculated for average pain intensity, peak pain intensity, and average pain unpleasantness. Of those considered at least modest responders on headache frequency, 7 of the 11 (63.6%) were considered at least modest responders for all 4 outcomes, 9 (81.8%) were considered at least moderate responders on 3 of the 4 outcomes, and 10 of the 11 (90.9%) were

Targeted Treatment to Reduce Catastrophizing considered at least modest responders on 1 other outcome. Further, 3 treatment completers (11.1%) who were considered nonresponders based on headache frequency were considered at least modest responders on all 3 of the other headache outcome variables. In addition, using the same standards for clinical improvement as indicated above for headache frequency, we calculated the percent change in medication use from 2 weeks immediately before treatment compared with the last 2 weeks of treatment. Medication use was calculated separately for abortive medications (primarily tryptans), nonopioid analgesics, and opioid analgesics by summing the number of days per week that medication use falling into each category was reported in the headache diary. Nine of the 27 completers considered reported using abortive medication during the 2 weeks immediately preceding treatment. Of those, 3 (33.3%) were considered responders (that is, showed a 50% or greater reduction in abortive medication use) and 1 (11.1%) was considered a modest responder (that is, showed a 25% to 49% reduction in abortive medication use). Thirteen of 27 participants reported using nonopioid analgesics during the 2 weeks preceding treatment. Of those, 7 (53.8%) were considered responders and 3 (23.1%) were considered modest responders based on reductions in nonopioid medication use. Nine of 27 completers reported opioid medication use during the 2 weeks preceding treatment. Of those, 4 (44.4%) were considered responders and 1 (11.1%) was considered a modest responder, based on reductions in opioid medication use. We also examined reductions in medication use in light of reductions in headache frequency. Twenty-one of the 27 considered participants reported using some type of medication at least once during the 2 weeks immediately preceding treatment. Seven (33%) of those participants were at least modest responders on both headache frequency and at least 1 category of medication use, and 1 (4.8%) participant was considered a responder based on headache frequency but did not report any significant changes in medication use. It is notable that 9 participants (42.9%) considered nonresponders, based on headache frequency were at least modestly responsive in reducing use of at least 1 form of medication, whereas 4 (19%) headache frequency nonresponders also did not significantly reduce use of 1 or more types of medication relative to pretreatment levels.

The Roles of Treatment Order and Catastrophizing in Treatment Outcome The MANOVA for treatment order did not approach significance for changes in outcome variables from pretreatment to post-treatment [F(9, 22) ⫽ 0.850, P ⫽ .581] or for changes in outcome variables from pretreatment to follow-up [F(5, 16) ⫽ 1.006, P ⫽ .446]; therefore, univariate tests were not conducted (see Table 3 for the means and standard deviations of change scores by group). With the current sample size, an effect size of 1.0 would be needed to attain a power of .80 for a two-

ORIGINAL REPORT/Thorn et al Table 4.

Changes in Outcome Measures for All Participants Across the Study Period

CHANGES

PCS BDI-II BAI PASS HMSE

947

FROM

PRE

TO

MIDTREATMENT

CHANGES

FROM

MID

TO

DIFFERENCES IN CHANGE SCORES BETWEEN TWO HALVES OF TREATMENT

POST-TREATMENT

MEAN CHANGE

SD

F(1,31)

d

MEAN CHANGE

SD

F(1,30)

d

⫺1.26 .41 .32 ⫺3.91 10.79

5.52 3.81 5.99 25.07 16.62

0.62 0.21 ⬍0.01 0.29 12.89†

.23 .12 .05 .16 .65

⫺2.98 ⫺2.91 ⫺3.66 ⫺4.86 11.45

6.07 4.58 6.49 16.95 12.16

7.21† 10.84† 9.97† 2.17 27.23†

.49 .64 .56 .29 .94

F(1,31) 1.67 6.48* 4.44* 0.01 0..01

d .22 .61 .57 .04 .03

NOTE. d represents the effect size for change scores. *P ⬍ .05. †P ⬍.01.

tailed test at P ⬍ .05. The multivariate test of the treatment order ⫻ pretreatment PCS scores interaction was not significant [F(5, 25) ⫽ 1.013, P ⫽ .43], so no further univariate analyses were conducted. MANOVA analyses indicated that, across all participants, there were not significant changes in treatment outcome measures from baseline to pretreatment [F(5, 28) ⫽ .428, P ⫽ .825]. However, when all participants were considered regardless of treatment order, the multivariate tests for changes during treatment were significant for pretreatment to midtreatment [F(5, 27) ⫽ 2.577, P ⫽ .05], and midtreatment to post-treatment [F(5, 26) ⫽ 7.170, P ⬍ .001]. From pretreatment to midtreatment, significant changes were only observed for the HMSE; however, from midtreatment to post-treatment, significant changes were reported in scores on the PCS, BDI, BAI, and HMSE (see Table 4 for results of univariate tests). A MANOVA comparing changes from the first half of treatment to the second half was not significant [F(5, 27) ⫽ 1.957, P ⫽ .118]. Univariate tests indicate that changes in BDI [P ⫽ .016, d ⫽ .61, and BAI, P ⫽ .045, d ⫽ .57] were significantly greater in the second half of treatment compared with the first half, regardless of which treatment module was presented first.

Discussion Chronic headache patients receiving CBT with an intensive cognitive component targeting pain catastrophizing reported significant changes on self-report measures of catastrophizing, anxiety, and headache management self-efficacy as compared with wait-list control subjects. Furthermore, participants showed significant post-treatment differences in headache frequency, peak intensity, catastrophizing, depression, anxiety, and headache management self-efficacy relative to their pretreatment baseline levels. Changes in catastrophizing, pain specific anxiety, and headache management self-efficacy were maintained at follow-up. Although changes in depression and anxiety at follow-up were medium in effect size, they were not statistically significant, probably due to

the relatively small sample size. Furthermore, approximately 40% of the participants were considered at least modest treatment responders based on percent reductions in headache frequency, and an additional 10% who were not deemed responders on frequency showed at least modest reductions in all other measures of headache activity (ie, average pain intensity, peak headache intensity, and average unpleasantness ratings). Thus, the treatment was effective for reducing cognitive and affective distress associated with the headaches, and in approximately 50% of the cases, the treatment produced clinically significant reductions in headache frequency or other measures of headache activity. There were no discernable differences between treatment responders and nonresponders on baseline demographics or pre-treatment headache indices, cognitive or affective measures, headache diagnoses, or medication use. The order of treatment modules (Cognitive Restructuring and Cognitive/Behavioral Coping) was not related to changes during treatment or at follow-up. The power for these tests was insufficient to have a reasonable expectation of detecting an effect unless it was large. These results do not rule out the possibility that treatment order effects went undetected. On the other hand, the results do not suggest that 1 treatment order will be found to be substantially more effective than the other as there was not even a small tendency for treatment order differences to occur for any of the outcome variables. Even for self-efficacy, in which very large changes occurred during treatment, there was no tendency for the groups to differ. It may be that a treatment dismantling design would be a better design to examine the specific mechanisms of CBT efficacy, and our future research is planned to involve such designs. For all participants, regardless of which treatment modules were received first, significant change only occurred in headache management self-efficacy from pretreatment to midtreatment (after the cognitive restructuring or the cognitive coping modules). From midtreatment to post-treatment (after all treatment modules), significant

948

Targeted Treatment to Reduce Catastrophizing

changes occurred in pain catastrophizing, depression, anxiety, and headache management self-efficacy. Changes in depression and anxiety scores were significantly larger in the second half of treatment than in the first half, regardless of which treatment module was presented first. Thus, although the order of treatment presentation does not appear to be important, longer participation in treatment (greater than 5 weeks) does seem to lead to more treatment gains. This finding speaks to the process of therapy and suggests that the treatment components build on each other over time to result in a cumulative effect. It may also indicate that it takes multiple sessions for the patients to begin to understand and utilize the material learned in CBT groups. Catastrophizing has been shown to mediate treatment outcomes in recent studies testing the effectiveness of psychosocial treatments for chronic pain.4,31,33 In the current study, catastrophizing was not shown to moderate treatment outcome and mediation was not tested; however, again the power to detect this effect was very small due to a limited sample size. Moreover, the mean pretreatment catastrophizing score for participants in this study (16.2) was considerably lower than the mean PCS score (28.2) reported by Sullivan et al,36 by patients undergoing evaluation and treatment at a multidisciplinary pain clinic. Based on their obtained norms, Sullivan et al concluded that patients scoring in the 80th percentile (scores above 38) are particularly at risk for adjustment difficulties and poor progress in pain rehabilitation programs. Thus, the levels of catastrophizing reported by the patients in our study did not approach a pathognomonic level. The effect size for change in headache management self-efficacy was over twice as large as the effect size for other outcome measures, indicating that self-efficacy levels were highly responsive to treatment. This could be a notable finding because research indicates that self-

efficacy (or lack there of) is a strong predictor of persistent disability and activity levels in patients with a variety of pain conditions including headache,3,8,28 even more so than pain intensity or duration in 1 study.5 Self-efficacy has been proposed as the mechanism of change for behavioral treatments for headache,27 although mediation per se has not been tested. Self-efficacy for managing pain has been associated with changes in other outcomes during treatment in patients with arthritis.16,17 Over and above catastrophizing and other pain related beliefs, selfefficacy has also been shown to be the only unique moderator of CBT treatment outcome for patients with temporomandibular disorder.42 More research is needed on the importance of self-efficacy in the attainment and maintenance of treatment gains. This study was limited by the relatively small sample size due to low availability of participants. Some analyses presented, such as comparisons between the wait-list and the immediate treatment group or comparison of treatment order, do not possess adequate power to detect a true effect. Furthermore, expectancy effects and demand characteristics associated with waitlist control designs may bias results in favor of the treatment groups.21 However, because most participants were already receiving medical treatment, the nature of the comparisons may actually diminish effect sizes. The benefits demonstrated in this clinical trial are likely above those produced by standard medical care alone. Future research may benefit from utilizing a more rigorous control condition, such as an attention control group. Even so, it is unrealistic to expect that those receiving psychosocial treatments and control comparison groups will not be simultaneously receiving medical treatment as usual. The improvements observed support the need for psychosocial interventions in chronic pain populations who are already receiving medical treatment.

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