Development and Validation of the Brief Support Group Leader Self-Efficacy Scale Among Scleroderma Peer Support Group...

Our objective was to develop a brief Support Group Leader Self-efficacy Scale (Brief-SGLSS) that maintains the core content and measurement properties of the full 32-item SGLSS among systemic sclerosis (SSc) support group leaders.

Development and validation involved four steps conducted by researchers and a Support Group Advisory Team of people with SSc: (1) item content assessment and prioritization, including a Delphi process; (2) item analysis and preliminary selection, including analysis of SGLSS measurement properties using Scleroderma Patient-centered Intervention Network-Scleroderma-Support group Leader Education (SPIN-SSLED) trial data and a data-driven item resampling process; (3) advisory team input to select final Brief-SGLSS items; and (4) comparison of convergent validity and trial change data of the Brief-SGLSS and full SGLSS.

Items were categorized into six content themes. Two Delphi rounds resulted in one item excluded from consideration. A 6-item Brief-SGLSS was selected at the consensus advisory panel meeting based on the resampling process and content and statistical considerations. The Pearson correlation of the Brief-SGLSS and full SGLSS was 0.96. The standardized mean difference between intervention (n = 74) and waitlist (n = 72) groups in the SPIN-SSLED trial immediately post intervention was 0.93 (95% confidence interval [CI] 0.59-1.27) for the full 32-item SGLSS and 0.93 (95% CI 0.58-1.27) for the Brief-SGLSS. Convergent validity of the Brief-SGLSS and full SGLSS with other measures was similar.

The 6-item SGLSS is shorter and more feasibly implemented than the full SGLSS and maintains similar measurement properties.