ABSTRACT
INTRODUCTION: The treatment of type 2 diabetes requires multidimensional management, with medication adherence a crucial aspect of diabetes control. However, recent rigorous estimates of adherence to oral antidiabetic drugs (OAD) are lacking. The objective of this study is to determine the prevalence of adherence to OAD in type 2 diabetes patients. METHODS: A systematic search was performed in PubMed, EMBASE, PsycINFO, and CINAHL from July 2013 to April 2023. Cross-sectional studies published in English were included if they met the following criteria: (1) reported the adherence to OAD using a validated measure; and (2) had a sample size of at least 385 patients with type 2 diabetes. The Joanna Briggs Institute critical appraisal for studies reporting prevalence data was used to assess the quality of the included studies. Pooled estimates of the prevalence of adherence to OAD were calculated as a percentage together with 95% confidence interval (95% CI) using a random-effect model. All analyses were conducted using STATA 17.0; PROSPERO (CRD42023414264). RESULTS: Twenty-six studies involving a total of 69,366 patients met the selection criteria and were included in the meta-analysis. The overall estimated prevalence of adherence to OAD was 55.53% (95%CI: 44.22%-66.85%). Among the included studies, nine were deemed to be of high quality. A sensitivity analysis conducted using only the high-quality studies revealed a prevalence of adherence to OAD at 52.24% (95% CI: 39.63%-64.85%). CONCLUSIONS: The overall prevalence of adherence to OAD was remarkably low among type 2 diabetes patients worldwide. Healthcare practitioners and policy makers should employ appropriate approaches to improve adherence to OAD.