Adherence to Glyburide and Metformin and Associated Factors in Type 2 Diabetes in Isfahan, Iran

The purpose of this study was to determine the adherence to oral hypoglycemic medications and associated factors in type 2 Diabetes Mellitus patients who were referred to the Isfahan Endocrinology and Metabolism Research Centre (IEMRC). Convenience sampling was used to enroll 248 patients with type 2 diabetes in a prospective study at IEMRC from January 2007 to January 2008. Patients had to be on a stable dose of oral hypoglycemic medications (glyburide and metformin) or for 3 months prior to the study and willing to participate in consultation sessions with a pharmacist. Pill count and self report methods were used to measure the adherence. Mean (SD) of patients studied was 56.6 (8.9) years and 62% were females. The mean (SD) duration of diabetes in the study patients was 10.8 (6.1) years and 81.9% of them were literate with basic education. Non-adherence rates to metformin and glyburide were recorded in 39.7% and 35.3% of the study population respectively. Lower HbA1C levels and higher education were associated with higher adherence rates. Forgetfulness, confusion, fasting, adverse effects, complexity of medication regimen and disruption of routines were most commonly reported causes of non adherence. Prevalence of adherence to these two medications did not differ significantly between pill count (62.3%) and self report (62.8%), (p >0.05). Adherence rates did not vary by pill count and self report significantly. It was concluded that good adherence to medications was associated with a lower HbA1C profile; so it seems that pill count is a useful method in the clinical practice to identify non-adherent patients. Further studies are needed to find out efficient interventions to improve the patient's adherence.