Medication Adherence in Type 2 Diabetes Patients in Nigeria

BACKGROUND: Medication adherence is a major universal factor influencing patient health outcomes, particularly in chronic diseases such as diabetes. Poor adherence to antidiabetes medication can cause therapeutic failure, leading to manifestation of diabetes-related complications, such as retinopathy, neuropathy, nephropathy, etc., reduced quality of life, and increased healthcare costs. To forestall these, likely predictors of medication nonadherence should be assessed and addressed appropriately. The purpose of this work was therefore to assess medication adherence among type 2 diabetes patients and to identify patient characteristics and probable factors associated with nonadherence. SUBJECTS AND METHODS: A descriptive, cross-sectional research design was used. The study was conducted on 360 ambulatory type 2 diabetes patients attending an endocrinology clinic between June 2012 and February 2013. The eight-item Modified Morisky Adherence Scale was used to assess medication adherence; sociodemographic information and respondents' opinion on the possible barrier(s) to medication adherence were also obtained. Data were analyzed using SPSS version 14.0 software (SPSS, Inc., Chicago, IL). RESULTS: Of the 303 patients included in the final analysis, 19.8% of respondents were judged to be highly adherent. Medium and low adherers were 30.0% and 50.2%, respectively. The median adherence score was 5.75 (interquartile range, 4.5-7.0). Adherence to medication correlated with low literacy level (P=0.008), forgetfulness (P=0.009), high cost of medication (P=0.014), limited access to care (P=0.001), complexity of regimen (P=0.001), poor patient-provider communication (P=0.000), lack of trust in the provider (P=0.046), and depression (P=0.031). No statistically significant relationship was found between patients' characteristics and medication adherence. CONCLUSIONS: Medication adherence was generally poor among the cohorts studied.