Society of Diabetic Nephropathy Prevention Journal of Nephropathology 2251-8363 10 1 2021 01 01 Development, reliability and validity of health action process approach questionnaire for predicting treatment adherence among Iranian hemodialysis patients e04 e04 10.34172/jnp.2021.04 EN Sadaf Sadeghi https://orcid.org/0000-0002-5217-1755 Mohammad Hossein Kaveh https://orcid.org/0000-0002-9141-3243 Shahrokh Ezzatzadegan Jahromi https://orcid.org/0000-0002-3606-2022 Haleh Ghaem https://orcid.org/0000-0001-9564-392X Hossein Ali Nikbakht https://orcid.org/0000-0002-8556-431X Journal Article 10.34172/jnp.2021.04 2020 01 04 2020 05 02 Introduction: End-stage renal disease (ESRD) is an advanced stage of chronic kidney disease requiring hemodialysis (HD). The long-term efficacy of HD in ESRD patients highly depends on treatment adherence. Objectives: This study aimed to validate the health action process approach (HAPA) questionnaire to predict treatment adherence in HD patients. Patients and Methods: This cross-sectional study was conducted in teaching hospitals in Shiraz during 2018. A total of 220 patients with ESRD under HD were selected using convenience sampling method. Furthermore, the validity, clarity, and comprehensiveness of the questionnaire were validated by a group of patients and experts. Then the exploratory factor analysis (EFA) was performed, and the reliability was determined using Cronbach’s alpha. Internal consistency was assessed using test-retest method (one-month interval) and calculating intra-class correlation coefficient (ICC) index. Results: Content validity index (CVI) and content validity ratio (CVR) were obtained 0.98 and 0.95 respectively indicating adequate content validity. Six constructs (risk perception, action self-efficacy, behavioral intention, planning, maintenance self-efficacy and recovery self-efficacy) were extracted using EFA. These constructs explained 51.4% of total variance. The Cronbach’s alpha of different constructs ranged from 0.68 to 0.82. Furthermore, the ICC ranged from 0.67 to 0.78 indicating an acceptable internal consistency. Conclusion: The HAPA questionnaire is a valid and reliable tool for assessing treatment adherence in HD patients. Further studies are recommended on larger sample sizes and other Iranian populations.