ECLIPSE compared a 6-month peer coaching self-management intervention to a control group consisting of a 2-hour pain self-management class. This control group was chosen because our purpose was to understand the role of peer support in facilitating self-management, rather than to understand the effects of self-management itself. Thus, the control class covered self-management topics but did not offer ongoing contact, support, or encouragement to patients. Participants were recruited from August 2015 to August 2018 and were veterans receiving care from one of six primary care clinics at a Midwestern VA Medical Center. Details of the trial protocol have previously been described.14
Intervention
A detailed description of the ECLIPSE intervention is available elsewhere.14 In brief, 68 peer coaches were enrolled. After a 2- to 3-h training session, peer coaches were assigned patients matched on gender and, when possible, pain location. Each coach was assigned one patient to start, and coaches could choose how many patients they wanted to mentor. Almost half (47%) chose to coach just one patient. With the patient’s permission, coaches were given their contact information and asked to call their assigned patient. Coach-patient pairs chose whether they wanted to meet in person or via telephone and were asked to meet/talk at least two times per month, for a total of 12 sessions over the 6-month intervention period. Check-in calls were conducted by study staff to ensure peer coaches and patients made contact and to assist when contact had not been made. Coaches and patients were guided by a manual focused on pain self-management, although coaches were instructed to be flexible and were encouraged to discuss their personal experiences with pain self-management and how they overcame challenges. Manual topics are covered in detail elsewhere14 but include relaxation skills, activity pacing, cognitive behavioral skills, and self-care skills. In addition, coaches were asked to participate in monthly “booster” sessions to reinforce coaching skills, answer questions, and troubleshoot problems. Coaches were not compensated for sessions but were compensated for completing outcome assessments (see the “Outcome Measures” section). Patients randomized to the control group were offered a 2-hour pain self-management class, which covered the same general topics listed above.
Participants
Eligible patients met the following criteria: (1) musculoskeletal pain in the low back, cervical spine, or extremities (hip, knee, or shoulder) for ≥ 3 months; (2) at least moderate pain severity, defined by pain ≥ 5 on a 0 (no pain) to 10 (worst pain imaginable) scale; and (3) willingness to engage in phone or in-person contact on a regular basis with another patient. Patients were excluded if the electronic medical record review indicated (1) psychiatric hospitalization in the last 6 months; (2) current substance dependence; (3) severe medical conditions precluding participation (e.g., New York Heart Association Class III or IV heart failure); (4) if the eligibility screener given to prospective participants revealed active suicidal ideation, severe hearing or speech impairment, or pending surgery for a musculoskeletal condition (e.g., back surgery); or (5) current participation in another pain study. Primary care providers granted permission to recruit their patients. Peer coaches had musculoskeletal pain in the low back, cervical spine, or extremities (hip, knee, or shoulder) for ≥ 3 months and were either completers of a prior pain self-management intervention, recommended by their primary care providers because their providers believed that they were successful pain self-managers, or completers of the ECLIPSE intervention as a patient.
Randomization
Following the baseline interview, participants were randomized to either the intervention or control group. To obtain random treatment assignment for the 215 patients (95 control, 120 intervention), permuted block randomization was used so that within each block the allocation ratio was maintained (19 control group: 24 intervention group).
Outcome Measures
Assessments were conducted at baseline, 6 months, and 9 months and administered to both patient participants and peer coaches, who were compensated $30 per completed assessment. The primary outcome measure was the Brief Pain Inventory (BPI) total score, which assesses pain severity and impact on function and is scored on a 0–10 scale with higher scores representing more severe and functionally limiting pain. Demographic measures and baseline primary and secondary outcome measures are summarized in Table 1 and described in detail elsewhere.14 Healthcare utilization measures were also considered secondary outcomes and were obtained through chart review. These measures included phone/secure messaging, outpatient visits, emergency department visits, hospitalizations, hospital days, and opioid medications during the 9-month study.
Table 1 Baseline characteristics Statistical Analysis
Sample size was determined to ensure adequate power for the primary hypothesis that patients randomized to peer support will experience greater improvement in pain (BPI total) than patients in the control arm at the 6-month endpoint. ECLIPSE was powered to detect a small to medium effect size of 0.45.15
Primary analyses employed an intent-to-treat approach. Baseline patient characteristics were compared using appropriate test statistics (Chi-square test, Fisher’s exact test, t-tests, or Wilcoxon rank-sum tests) to verify that randomization achieved balanced groups. For the primary outcome of total BPI score, a linear mixed model was fit and included fixed effects of time as categorical, group, and the time X group interaction. Random effects included a random patient-specific intercept and a random effect for peer-coach in the intervention group only to account for the potential correlation of outcomes from patients assigned the same peer coach.16 The primary contrast of interest is the difference in change from baseline at 6 months between the two treatment arms. For BPI subscales of pain severity and interference as well as secondary outcomes, a Sidak adjustment was used to account for multiple comparisons at a given time point.
For healthcare utilization measures (phone/secure messaging, outpatient visits, emergency department visits, hospitalizations, hospital days, and opioid use over the 9-month study period), a generalized linear mixed model was used, assuming that the counts follow a negative binomial distribution with a group indicator as the only fixed effect. All analyses were conducted in SAS V9.4 (Cary, NC) with significance level set at 0.05.
Exploratory Analyses
Intervention Dose
The number of meetings with the peer coach was self-reported by the patient and was available for 84 intervention participants (70.5%). Fifty-four patients (64%) had 5 or fewer contacts with their peer coach. To ascertain whether an intervention effect was present among patients who had closer to the recommended 12 contacts, we focused on the 30 patients who had at least 6 peer coach meetings. Toward this end, the primary linear mixed models were fit to this subset of patients and all control patients.
Moderation
Baseline patient activation was explored as a potential moderator of the intervention effect using the linear mixed models for the primary and secondary outcomes with the addition of all 2- and 3-way interactions between the potential moderator (patient activation), group, and time. Moderation occurs if the 3-way interaction is statistically significant.