Differences in pharmacotherapy and in glucose control of type 2 diabetes patients in two neighbouring towns:: a longitudinal population-based study

Aim: To compare prescribing, dosage and blood glucose levels in patients with type 2 diabetes in two communities with differences in anti-hyperglycaemic drug utilization. Methods: A retrospective longitudinal (1984-1994) population-based study in two neighbour towns in southern Sweden, The mean prescribed daily dose was expressed as a fraction of the Defined Daily Dose (DDD) for each drug. Results: In town A, prescribing of oral agents and insulin was predominantly made by one specialized diabetes clinician, while in town B it was spread among several different general practitioners and one specialist, Altogether 44 636 medical visits by 2348 patients were identified. In each town, about 40% of the patients were treated without anti-hyperglycaemic drugs, about 40% with oral agents and about 20% with insulin. However, there were pronounced between-town differences in dosage and glucose control. The mean prescribed daily dose of sulphonylurea monotherapy decreased gradually from approximate to 0.7 to approximate to 0.5 DDD in town B but remained approximate to 0.8 DDD in town A. The proportion of patients on both sulphonylurea and metformin increased substantially in town A but not in town B. In these patients, the mean prescribed daily dose of sulphonylurea exceeded 1.0 DDD in both towns, although it decreased with time in town B. The mean prescribed daily dose of insulin increased from 1.05 to 1.2 DDD in town A but remained virtually unchanged at 0.95 DDD in town B. The mean fasting blood glucose was lower in town A than in town B both overall (7.7 vs. 8.8 mmol/l), in those treated without any anti-hyperglycaemic drugs (7.2 vs. 8.1 mmol/l), in those on sulphonylurea monotherapy (8.3 vs. 9.7 mmol/l) and in those treated with insulin (8.1 vs. 10.2 mmol/l). Conclusions: Glucose control in routine care was better when most patients were treated by a diabetes specialist and were exposed to more intense pharmacotherapy.