Refill adherence to oral antihyperglycaemic drugs in Sweden

Only 49% of the patients with T2D in Sweden that medicate with oral antihyperglycaemic drugs (AHGD) had good blood glucose control (HbA1C < 6.0%). The reason can be low medication adherence. The aim of this study was, therefore, to determine the adherence to different oral AHGD. Included were all patients in Sweden, older than 40 years and having at least two expenditures of AHGD between 1 December 2005 and 30 November 2006. After exclusions of inpatients and patients with unspecified daily dosage 171,220 patients (57% men) remained. Medication possession ratio (MPR) was used for estimating adherence and patients were regarded adherent if MPR ≥80%. The overall refill adherence average 90%, with mean MPR (SD) = 107% (30). Eighty-five percent of the patients in their 40s were adherent compared to 91% of the patients in their 80s. About 90.1% of the women were adherent whereas 89.5% of the men were adherent. Patients with an indication for the medicine were more adherent than patients without this information. We conclude that the unsatisfactory blood glucose control showed among many Swedish T2D patients is not the result of non-adherence to prescribed medication.