Background: Arthritis is a prevalent and disabling source of chronic pain for which African Americans (AAs) bear a disproportionate burden. The purpose of this study is to test a patient-centered, non-invasive intervention to improve pain outcomes and reduce disparities in AA and White Veterans with knee arthritis. The intervention is designed to help Veterans develop a positive mindset, the health benefits of which are well-documented.

Objectives: The primary aim of this study is to evaluate the impact of a positive intervention on pain and physical functioning in AA and White Veterans with knee arthritis through a randomized, controlled, clinical trial. It is hypothesized that patients randomized to a positive activities (PA) intervention will experience improved pain and functioning compared to patients randomized to an attention control (AC) program, and that these improvements will be larger for AA than for WH Veterans. The secondary aim of this study is to identify variables that mediate the effects of the PA intervention on pain and functioning. It is hypothesized that the effects of the PA intervention will be mediated by psychosocial variables known to be associated with arthritis outcomes or racial differences in arthritis outcomes (e.g., depression, self-efficacy, pain coping, perceived discrimination).

Methods: A randomized, controlled, 2-arm design will be used to compare the effects of a 6-week PA intervention with that of an AC program on pain and functioning at 1, 3, and 6-months post-intervention among AA and WH Veterans with knee arthritis. Approximately 180 AA and 180 WH primary care patients with knee pain symptoms consistent with arthritis will be recruited from participating VA medical centers following the original protocol. \[Due to accelerated recruitment of the original target sample, up to 240 additional primary care patients with knee pain symptoms consistent with OA will be recruited from participating VA medical centers using inclusion criteria that take into account original ICD-9 codes and their corresponding ICD-10 codes. The additional patients (including some men and some women, as resources allow) will be recruited to increase power to detect sex differences in secondary analyses after the primary aims of the study have been achieved using the original cohort.\] Eligible participants will complete an in-person baseline assessment of study outcomes, mediators, and control variables and be randomized to a 6-week PA or AC program. The PA program consists of completing 6 at-home activities (1 per week) that have been shown to increase positivity. The AC program consists of 6 affectively neutral activities. Both groups will receive weekly telephone calls from trained interventionists to clarify instructions for the next week's activity and assess completion of the previous week's activity. Outcomes and proposed mediating variables will be assessed via telephone surveys at 1 month, 3 months, and 6 months post-intervention. Study outcomes include self-reported pain and physical functioning as measured by the Western Ontario MacMaster Index. Hypothesized mediators include depressive symptoms, positive/negative affect, satisfaction with life, arthritis self-efficacy, pain coping, pain catastrophizing, perceived discrimination, global stress, and social support. The intervention impact over time and by race (primary aim) will be tested using linear mixed models that allow repeated measures on the continuous outcomes for each participant and assess change in outcomes over time. A multiple mediator bootstrap approach to assess whether the effect of the intervention is mediated by the hypothesized mediators.