Effect of a Positive Psychological Intervention on Pain and Functional Difficulty Among Adults With Osteoarthritis: A Randomized Clinical Trial.

Importance: Positive psychological interventions for improving health have received increasing attention recently. Evidence on the impact of such interventions on pain, and racial disparities in pain, is limited. Objective: To assess the effects of a positive psychological intervention on pain and functional difficulty in veterans with knee osteoarthritis. Design, Setting, and Participants: The Staying Positive With Arthritis Study is a large, double-blinded randomized clinical trial powered to detect race differences in self-reported pain in response to a positive psychological intervention compared with a neutral control intervention. Data were collected from 2 urban Veterans Affairs medical centers. Participants included non-Hispanic white and non-Hispanic African American patients aged 50 years or older with a diagnosis of osteoarthritis. Mailings were sent to 5111 patients meeting these criteria, of whom 839 were fully screened, 488 were eligible, and 360 were randomized. Enrollment lasted from July 8, 2015, to February 1, 2017, with follow-up through September 6, 2017. Interventions: The intervention comprised a 6-week series of evidence-based activities to build positive psychological skills (eg, gratitude and kindness). The control program comprised similarly structured neutral activities. Programs were delivered via workbook and weekly telephone calls with interventionists. Main Outcomes and Measures: The primary outcomes were self-reported pain and functional difficulty measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC; range 0-100). Secondary outcomes included affect balance and life satisfaction. Results: The sample included 180 non-Hispanic white patients and 180 non-Hispanic African American patients (mean [SD] age, 64.2 [8.8] years; 76.4% were male). Mean (SD) baseline scores for WOMAC pain and functional difficulty were 48.8 (17.6) and 46.8 (18.1), respectively. Although both decreased significantly over time (pain: χ23 = 49.50, P < .001; functional difficulty: χ23 = 22.11, P < .001), differences were small and did not vary by treatment group or race. Exploratory analyses suggested that the intervention had counterintuitive effects on secondary outcomes. Conclusions and Relevance: The results of this randomized clinical trial do not support the use of positive psychological interventions as a stand-alone treatment for pain among white or African American veterans with knee osteoarthritis. Adaptations are needed to identify intervention components that resonate with this population, and the additive effect of incorporating positive psychological interventions into more comprehensive pain treatment regimens should be considered. Trial Registration: ClinicalTrials.gov Identifier: NCT02223858.