National Background is Associated with Disparities in Initiation and Persistence to Statin Treatment in Subjects with Diabetes in Denmark

Background: To investigate the effects of statin use over the last 10 years among diabetic patients who initiated glucose-lowering medications (GLMs) in Denmark. Methods: we identified all Danish citizens 30 years and older who claimed their first GLM between 1997 and 2006, with follow-up until 2007. Use of medications, national background, income, and hospitalizations were obtained by cross-linkage of national registries in Denmark. We analyzed factors related to initiation and interruption of statin treatment. The analyses included country of birth, citizenship and, as proxy for ethnic origin, we constructed variables based on both the subjects and on their parent's country of birth. Countries were grouped as Denmark, Western countries, Eastern countries, and Africa. Results: the cohort included 143,625 subjects. Compared with persons of Danish origin, the initiation of a statin medication during follow-up was significantly lower among patients of non-Danish origin: Odds ratio for subjects of Eastern origin 0.61 [CI 0.49–0.76] and 0.37 for subjects of African origin, [CI 0.24–0.59], both p < 0.001. The risk of interrupting statin treatment once it had been initiated was also higher in these groups (hazard ratio 2.03, [CI 1.91–2.17] for Eastern subjects and 1.94, [CI 1.63–2.32] for African subjects, both p < 0.0001). Combination of ethnic parameters to refine identification of the cohort led to the same conclusions as the analysis based only on country of birth or citizenship respectively. Conclusion: diabetes patients of African and Eastern origin in Denmark have less chance of being treated with a statin than those of western and Danish origin despite similar access to the Danish health care system.