Tabriz University of Medical Sciences Journal of Caring Sciences 2251-9920 15 2 2026 05 25 Determinants of Medication Adherence in Older Adults with Type 2 Diabetes: A Systematic Review Based on the WHO Five-Dimensional Framework 136 151 10.34172/jcs.34974 EN Mahsa Sarvi https://orcid.org/0009-0005-0344-9801 Somayeh Hashemi https://orcid.org/0000-0001-5490-7714 Maryam Afshari https://orcid.org/0000-0001-5967-7575 Journal Article 10.34172/jcs.34974 2025 02 04 2025 08 31 Introduction: Medication non-adherence in elderly patients with type 2 diabetes mellitus contributes to poor disease control and complications. This systematic review aimed to systematically identify and classify the determinants of medication adherence in older adults with type 2 diabetes according to the WHO five-dimensional framework. Methods: This systematic review was conducted in accordance with PRISMA guidelines. A comprehensive search of PubMed, ScienceDirect, Web of Science, SAGE Journals, the Cochrane Library, Google Scholar, and Scopus were performed for English-language studies published from January 2000 to December 2024. Observational and qualitative studies conducted among adults aged≥60 years with type 2 diabetes were included if medication adherence was assessed using validated instruments or defined self-report measures. Study quality and risk of bias were evaluated using standardized appraisal tools. Due to substantial methodological heterogeneity across study designs and adherence measures, findings were synthesized narratively. Results: Of 1,143 identified records, 29 studies met the inclusion criteria. Factors associated with non-adherence, as reported in the included studies, included socio-demographic characteristics (younger age, male sex, single status, low income or education, and alcohol use), patient-related barriers, psychological comorbidities (anxiety and depression), and healthcare system constraints. Factors promoting adherence included structured healthcare support, better quality of life, simpler medication regimens, reduced medication costs, higher self-efficacy, stronger social support, spiritual coping, greater health literacy, positive treatment attitudes, and engagement in self-care behaviors. Conclusion: This review highlights modifiable barriers and facilitators to medication adherence in elderly patients with type 2 diabetes, supporting interventions like mental health integration and treatment simplification to improve outcomes.