Literacy-Adapted Cognitive Behavioral Therapy Versus Education for Chronic Pain at Low-Income Clinics

Chronic pain (that is, pain lasting beyond the usual course of illness or injury, usually longer than 3 to 6 months) is widespread, challenging to treat, and a growing problem (13). Approximately 20% of physician visits and 10% of drug sales are attributed to pain (1, 2). More than 116 million Americans have chronic pain, costing $600 billion annually (1, 3). Chronic pain disproportionately affects economically disadvantaged persons, ethnic minority groups, women, and older adults (2, 4), who have higher rates of chronic pain, greater risk for pain-related disability, and higher rates of major chronic physical and psychological comorbid conditions (1, 58). Standard approaches to chronic pain focus on expensive biomedical interventions and analgesic medications that are fraught with undesirable side effects, as exemplified by the spiraling opioid epidemic. Recently published national clinical practice guidelines stress nonpharmacologic, evidence-based alternatives to pain medications (911). However, many providers are not familiar with such treatments as cognitive behavioral therapy (CBT), and access to CBT is limited, particularly in low-income communities. Although CBT for chronic pain is effective (1214), rigorous trials have not been conducted in populations with low socioeconomic status (1, 2). Pilot research showed that group-administered CBT and pain education (EDU), adapted to reduce cognitive demands, were efficacious in persons with low socioeconomic status who have chronic pain (15). That trial was underpowered to detect differences between treatment groups and lacked a usual care comparison group, precluding evaluation of whether the interventions could augment existing practices (16). The purpose of this study was to compare literacy-adapted CBT, EDU, and usual care for treating chronic pain in a larger sample of patients with chronic pain. We hypothesized that participants randomly assigned to receive CBT or EDU would show greater posttreatment improvements in pain intensity, physical function, and depression than those receiving usual care and that CBT would be superior to EDU and usual care in reducing depression. Because of the highly disadvantaged nature of the population and anticipated difficulty reaching participants for follow-up, we defined posttreatment as our primary end point and did not make hypotheses about maintenance of effects at 6 months. Supplement. Study Protocol Methods Design Overview The LAMP (Learning About My Pain) study was a 3-group, parallel-design (1:1:1 allocation ratio), randomized controlled trial comparing CBT, EDU, and usual care in treating chronic pain (17). Participants were recruited from 12 September 2013 to 1 December 2015, and follow-up visits were completed by 30 September 2016. Although the trial registration was submitted to ClinicalTrials.gov in June 2013, required revisions delayed its final publication. Sixteen of 290 patients (5.5% of the sample) were enrolled before trial registration on 21 October 2013, but no outcome data were collected. Procedures were approved by the University of Alabama Institutional Review Board (IRB); minor protocol changes during the study are described in Appendix Table 1. Informed consent was obtained at enrollment. Appendix Table 1. IRB Modifications Throughout the LAMP Trial Setting and Participants Participants were recruited from 4 clinic sites in 36 separate cohorts at community health centers administered by Whatley Health Services (WHS), a private nonprofit agency in western Alabama that predominantly serves members of ethnic minorities with low socioeconomic status. Two WHS employees served as paid participant coordinators. Together, they recruited and screened potential participants for eligibility, followed all participants (including those in usual care), and facilitated retention. All WHS patients with a chronic painrelated diagnosis were contacted to determine their interest in participating in the study. Eligible persons were at least 19 years of age; had a chronic painrelated diagnosis, with pain most days of the month for at least 3 months; were proficient in English; and provided a means of contact. Exclusion criteria were pain related to cancer, clinically significant cognitive impairment, current self-reported substance abuse, serious uncontrolled mental illness, a reading level below first grade, recent changes in pain or psychotropic medication (in the previous 4 weeks), and current psychosocial treatment for pain (Figure 1). Figure 1. Flow of participants through the trial with usual care, CBT, and EDU. CBT= cognitive behavioral therapy; EDU= pain education. Randomization and Interventions The study statistician used statistical software to generate a random-number table that stratified treatment assignments by site (n= 4, with intentional weighting toward the highest-volume site) and was balanced by treatment group (n= 3). At each site, participants were assigned to cohorts of 7 to 9 persons per group. Cognitive behavioral therapy and EDU were administered in group format by co-therapists. Both interventions were the result of adaptations begun in previous research to simplify treatment procedures and revise patient workbooks to a fifth grade reading level (15, 18). The patient workbooks and therapist supplements are copyrighted but freely available at pmt.ua. edu/publications.html. Each participant received a workbook and weekly audio CD with a summary of that week's material. For the CBT groups, CDs included instructions for skills practice and a relaxation exercise. Participants were compensated $20 per session for travel to the group sessions, with no additional compensation for attendance. CBT: LAMP Group The CBT treatment manual used in this study is standardized and supported by empirical studies (15, 19). Ten weekly 90-minute group sessions provided simplified cognitive behavioral techniques, including motivational reinforcement, pain education, and pain management skills training (such as cognitive restructuring, activity pacing, and relaxation). EDU: LAMP Group Ten weekly 90-minute group sessions provided relevant pain-related information aimed toward pain self-management and group discussion, but no specific skill-building exercises were taught. The EDU program was matched to the CBT intervention with regard to format, discussion, and therapist engagement; it is standardized and supported by empirical research (15, 18, 20). Both Groups All participants received usual medical care, which may have involved any nonpsychological pain management method, including medication, chiropractic, or physical therapy, through WHS or external providers. Those randomly assigned to usual care had parallel contact with participant coordinators and assessors, as well as intermittent phone contact to facilitate retention, but received no psychosocial treatment. Therapists worked in pairs of 1 doctorate-level psychologist and 1 predoctoral clinical psychology trainee (total of 10 therapists: 5 doctoral, 5 predoctoral). Training for the CBT and EDU therapists, as well as supervision of ongoing therapy, was provided by using the standardized CBT and EDU materials. All sessions were video recorded, and a study investigator uninvolved in treatment used a structured scale (21) to evaluate the therapists' adherence to the protocol and the quality of the intervention for 26.7% of the sessions (randomly selected) (Appendix Table 2). Appendix Table 2. Summary of Treatment Integrity Process for the LAMP Protocol* Blinding Study participants and patient coordinators were not blinded to treatment allocation but were unaware of the study hypotheses. Therapists were not blinded to participants' treatment assignment for the groups they led. Study outcomes were collected by blinded, trained assessors. Because the principal investigator supervised the therapists, she was not blinded to participants' assignment status; however, she did not conduct outcome assessments, nor was she one of the medical providers following the patients. Outcomes and Follow-up Assessors conducted face-to-face, 90-minute interviews, presenting assessment materials verbally. Assessment data were collected at baseline (before randomization), 5 weeks after the start of treatment (mid-treatment), at 10 weeks (posttreatment), and 6 months after treatment. Participants were compensated $45 for each assessment. Outcomes were prespecified as primarypain intensity, assessed by using the 4-item Brief Pain InventoryShort Form (BPI-SF) Pain Intensity subscaleand secondaryphysical function, measured by the BPI-SF Pain Interference subscale (22), and depression, measured by the Patient Health Questionnaire9, (PHQ-9) (23). Patient Global Impression of Change (24) was a secondary outcome evaluated in the study but not reported here. At baseline, sociodemographic and pain information was obtained, including self-reported methods to manage pain, and data regarding opioid prescriptions were collected from medical records. Primary literacy also was assessed with the Wide Range Achievement Test 4 Word Reading Subtest (25). Treatment adherence was defined as the number of CBT or EDU group sessions attended, and adequate dosage was defined as attendance at more than 6 sessions. Self-reported adverse events (emergency room visits, hospitalization, suicidal ideation) were queried weekly by therapists for participants in the CBT and EDU groups and by assessors at mid-treatment and posttreatment for all participants (including those receiving usual care). Identified adverse events were documented in compliance with IRB policies, and IRB staff ultimately determined whether each event was related to the study. An external data safety officer monitored all trial safety procedures and events, as did the IRB and principal investigator. Statistical Analysis Sample size was estimated by using the smallest expected between-group effect: the difference between groups across time in dep