RESUMO
OBJECTIVE: To develop a valid and reliable tool to evaluate access to, and use of, medicines at household level (HH-ATM tool). STUDY DESIGN: The Behavioral Model of Health Services Use was adapted and used as the conceptual framework for developing the HH-ATM tool. Questionnaires were designed (individual and household) based on the conceptual framework and existing tools, including items that captured the characteristics of predisposing, enabling and need factors; health care behaviours; outcomes and impacts. METHODS: Face validity, content validity and test-retest reliability were assessed using inter-rater agreement, item and scale content validity indices, comprehensiveness indices, and intra-class correlation, kappa and weighted-kappa coefficients. RESULTS: The household and individual questionnaires demonstrated appropriate validity and reliability. The content validity of household questionnaire was favourable, with inter-rater agreement of 86% and 91% for relevance and clarity, respectively. Scale content validity indices for relevance and clarity were 89% and 91%, respectively, and comprehensiveness was scored at 100%. These indices were also favourable for the individual questionnaire, all scoring 94% or higher. CONCLUSION: The questionnaires showed excellent validity and reliability for use in Iran. The HH-ATM tool can be implemented to evaluate access to, and use of, medicines in Farsi-speaking communities, and may be useful in other communities if adapted appropriately.