Adherence to hypoglycaemic medication among people with type 2 diabetes in primary care.

Abstract

To assess levels and correlates of adherence to hypoglycaemic medication among patients offered organised general practice diabetes care. 60 patients prescribed oral hypoglycaemic medication were recruited to a two-month prospective study. Prescribed doses taken and days on which the prescribed number of doses was taken were measured by MEMS (Medication Event Monitoring System). Overall 99.1% of prescribed doses were taken (median, IQR: 96.8-100%), this was inversely correlated with daily dose frequency (Spearman's rho=0.37, p=0.004). Only 4 patients (6.7%) took less than 90% of prescribed doses. The prescribed dose was taken on 96.4% of days (median, IQR: 89.1-98.2%), this was correlated with age (rho=0.26, p=0.047) and inversely correlated with HbA(1c) levels (rho=-0.29, p=0.02) and daily dose frequency (rho=-0.33, p=0.009). Adherence to metformin was less than to other hypoglycaemic medication (Z=-3.48, p=0.0005). A dispensing practice with a well-run diabetes service can support high rates of adherence to hypoglycaemic medication. Before changing medication, low adherence might be considered as a possible cause of progressive hyperglycaemia, particularly among patients prescribed metformin more than once a day. Selective monitoring with MEMS may have a clinical as well as a research role in such people.