Lessons in Affect Regulation to Keep Stress and Pain UndeR control (LARKSPUR): Design of a randomized controlled trial to increase positive affect in middle-aged and older adults with fibromyalgia

Background: Fibromyalgia syndrome (FMS) is a leading cause of functional limitations and disability for which there is no cure. Positive psychological interventions for improving health have received increasing attention, but evidence of the feasibility, acceptability, and impact of such interventions in adult populations with FMS is limited. Objectives: To describe the rationale and design of a 5-week, online positive affect skills intervention, LARKSPUR: Lessons in Affect Regulation to Keep Stress and Pain UndeR control. Methods: FMS participants (N = 90) will be randomized to one of two conditions: (1) LARKSPUR or (2) emotion reporting/attention control. LARKSPUR is an online multicomponent intervention that targets eight skills to help foster positive affect: (1) noticing positive events, (2) savoring positive events, (3) identifying personal strengths, (4) behavioral activation to set and work toward attainable goals, (5) mindfulness, (6) positive reappraisal, (7) gratitude, and (8) acts of kindness. The primary outcomes include feasibility (i.e., recruitment, retention, adherence) and acceptability (i.e., helpfulness, usability, satisfaction). Secondary outcomes include pain intensity and pain interference. Significance: If feasibility and acceptability metrics are met and reductions in pain outcomes are achieved, we will undertake future efficacy and effectiveness trials of LARKSPUR among older adults with FMS. Trial Registration: NCT04869345.