Impact of Socioeconomic Factors and Gender on Refill Adherence and Persistence to Lipid-Lowering Therapy in Type 1 Diabetes

Introduction: Lipid-lowering therapy (LLT) reduces the risk of cardiovascular disease (CVD) in patients with type 1 diabetes (T1D). However, socioeconomic factors and gender may have an impact on the adherence to and non-persistence with LLT.

Methods: This was a nationwide register-based cohort study that included 6192 individuals with T1D aged ≥ 18 years who were registered in the Swedish National Diabetes Register and had initiated novel use of LLT. Information on socioeconomic parameters (source: Statistics Sweden) and comorbidity (source: National Patient Register) was collected. The individuals were followed for 36 months, and adherence to LLT was analyzed according to age, socioeconomics and gender. The medication possession ratio (MPR; categorized into ≤ 80% and > 80%) and non-persistence (discontinuation) with medication was calculated after 18 and 36 months.

Results: Individuals older than 53 years were more adherent to LLT (MPR > 80%) than those younger than 36 years (odds ratio [(OR] 1.30, p < 0.0001) at 36 months. Women were more adherent and less prone to discontinue LLT at 18 months (OR 1.05, p = 0.0005 and OR 0.95, p = 0.0004, respectively), but not at 36 months. Divorced individuals were less adherent than married ones (OR 0.93, p = 0.0005) and discontinued LLT more often than the latter (OR 1.06, p = 0.003). Education had no impact on adherence, but individuals with higher incomes discontinued LLT less frequently than those with lower incomes. Individuals with a country of origin other than Sweden discontinued LLT more often.

Conclusion: Lower adherence to LLT in individuals with T1D was associated with male gender, younger age, marital status and country of birth. These factors should be considered when evaluating adherence to LLT in clinical practice, with the aim to help patients achieve full cardioprotective treatment.