Development and Validation of Instruments to Measure Medication Adherence in Hypertensive Patients (MAHP): The Indonesian Case

Background: Hypertension is a chronic disease that poses a significant public health issue globally. Medication adherence among hypertensive patients remains low, leading to various complications that adversely affect individuals, families, and the broader economy and society. To our knowledge, no specific instrument exists to measure medication adherence in hypertensive patients (MAHP) exclusively. This study aims to develop and validate an instrument to measure medication adherence and adherance-related behaviors among hypertensive patients. Methods: The research consisted of two methods: (1) scale construction and (2) scale validation. The construction phase included: (1) defining the construct and its domains, (2) item development, (3) expert review using the Content Validity Index (CVI), and (4) assessing readability through response process testing. The validation phase included: (1) exploratory factor analysis (EFA), (2) confirmatory factor analysis (CFA), and (3) reliability testing using Cronbach’s alpha. Results: EFA revealed four domains consistent with those identified through literature review and focus group discussions. However, item allocation led to renaming of certain domains. CFA confirmed that the resulting model had good fit. Conclusion: The MAHP scale, consisting of four domains and eleven items related to medication adherence in hypertensive patients, has demonstrated sufficient evidence of its validity. Keywords: Hypertension, Instrument, Medication adherence, Hypertensive patients, Indonesia