Development of a measure of self-efficacy for acute headache medication adherence.

Acute medication adherence is essential to manage chronic, episodic disorders, including headache. This paper describes the development of a measure of acute medication self-efficacy for headache (AMSE-H). Phase 1: 14 AMSE-H items were generated through qualitative interviews with 21 patients and 15 clinical headache experts. Phase 2: Researchers selected 7 AMSE-H items by examining item performance in 35 headache patients. Phase 3: Migraine patients (n = 161) completed the AMSE-H, and measures of outcome expectancies, perceived access to medication, headache management self-efficacy (n = 58) and a 1-week AMSE-H re-test (n = 103). Content validity was established through input of multiple stakeholder groups during item generation. PCA identified two components: cross-episode self-efficacy (eigenvalue = 3.4) and Episode-Specific Self-Efficacy (eigenvalue = 1.0). These subscales are internally consistent (.73-.80), have low 1-week test-retest reliability (rs = .52-.66), and demonstrated solid construct and discriminant validity. The AMSE-H is brief, theory-driven, focused, socially valid measure acceptable to both patients and providers.