Medication adherence among patients with Type 2 diabetes: A mixed methods study

Objective: Oral hypoglycemic agents (OHAs) are highly effective in managing Type 2 diabetes if taken appropriately. This study assessed adherence to OHAs among patients with Type 2 diabetes and explored factors associated with adherence behaviour. Research design and methods: Mixed methods were used comprising a cross-sectional study using the Arabic version of the Morisky Medication Adherence Scale followed by semi-structured interviews using the Theoretical Domain Framework to explore key determinants of adherence. Results: The cross-sectional study included 395 patients of whom 40% achieved a high level of OHA adherence. Lower adherence was associated with younger age (Odds Ratio (OR) 1.084; 95% CI 1.056 to 1.112), higher numbers of non-OHAs (OR 0.848; 95% CI 0.728 to 0.986) and higher HbA1c levels (OR 0.808; 95% CI 0.691 to 0.943). Semi structured interviews based on the Theoretical Domain Framework were completed with 20 patients and identified a wide range of factors potentially associated with OHA adherence, particularly behavioural related factors (e.g. scheduling medication intake, ability to develop a habitual behaviour), social influences (e.g. acting as a role model, the effect of family support), and gaps in knowledge about diabetes and its management with OHAs. Conclusions: This unique mixed-methods study has highlighted possible reasons for the low levels of OHA adherence in this patient population. Whilst the theoretically-derived determinants of behaviour illustrate the complexities associated with OHA adherence, they also provide a robust underpinning for future intervention(s) development to improve adherence and maximise patient health outcomes.