Treatment choice, medication adherence and glycemic efficacy in people with type 2 diabetes: a UK clinical practice database study

OBJECTIVE: Using primary care data obtained from the UK Clinical Practice Research Datalink, this retrospective cohort study examined the relationships between medication adherence and clinical outcomes in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: Data were extracted for patients treated between 2008 and 2016, and stratified by oral antihyperglycemic agent (OHA) line of therapy (mono, dual or triple therapy). Patients were monitored for up to 365 days; associations between medication possession ratio (MPR) and outcomes at 1 year (glycated hemoglobin A1c (HbA1c), weight and hypoglycemia incidence) were assessed using linear regression modeling and descriptive analyses. RESULTS: In total, 33 849 patients were included in the study (n=23 925 OHA monotherapy; n=8406 OHA dual therapy; n=1518 OHA triple therapy). One-year change in HbA1c was greater among adherent (−0.90 to −1.14%; −9.8 to −12.5 mmol/mol) compared with non-adherent patients (−0.49 to −0.69%; −5.4 to −7.5 mmol/mol). On average, adherent patients had higher hypoglycemia event rates than non-adherent patients (rate ratios of 1.24, 1.10 and 2.06 for OHA mono, dual and triple therapy cohorts, respectively) and experienced greater weight change from baseline. A 10% improvement in MPR was associated with −0.09% (−1.0 mmol/mol), −0.09% (−1.0 mmol/mol) and −0.21% (−2.3 mmol/mol) changes in HbA1c for OHA mono, dual and triple therapy cohorts, respectively. CONCLUSIONS: For patients with type 2 diabetes, increasing medication adherence can bring about meaningful improvements in HbA1c control as the requirement for treatment escalation increases. Regimens associated with weight loss and the avoidance of hypoglycemia were generally associated with better medication adherence and improved glycemic control.