Development and Validation of a Culturally Adapted Patient Activation Instrument for Medication Adherence in Chronic Disease Populations Across Northern Nigeria

Patient activation, defined as an individual's knowledge, skill, and confidence to manage their own health, is a powerful predictor of medication adherence and chronic disease self-management. Existing patient activation instruments have been developed and validated in Western contexts and lack cultural adaptation for northern Nigerian populations, whose health beliefs, literacy levels, and social structures differ substantially from those informing current tools. This study developed and validated a culturally adapted patient activation instrument for medication adherence assessment in chronic disease populations across northern Nigeria, encompassing the North West, North East, and North Central zones. A seven-phase instrument development process was undertaken, beginning with systematic review of patient activation constructs, followed by focus groups with 72 patients and 24 healthcare providers across the three zones to establish cultural domains, expert panel review, cognitive interviewing in Hausa and other regional languages, and pilot testing. Psychometric validation was conducted with 890 chronic disease patients using confirmatory factor analysis, Rasch analysis, test-retest reliability assessment, and criterion validity testing against the eight-item Morisky Medication Adherence Scale and health literacy measures. The final 24-item instrument demonstrated excellent structural validity, with three culturally derived factors capturing knowledge-confidence, social support activation, and provider interaction quality. Internal consistency alpha was 0.89, and test-retest reliability was 0.84. Criterion validity correlations with adherence scales were significant across all zones. This validated instrument fills a critical research and clinical gap for assessing and monitoring patient activation in northern Nigerian healthcare settings. Keywords: patient activation, instrument development, medication adherence, northern Nigeria, psychometric validation