Keeping up with guideline recommendations: does patient volume matter in diabetes care?

To examine the association between service volume and guideline adherence via multiyear observations.

Repeated cross-sectional study.

This study employed nationwide claims data from Taiwan's National Health Insurance scheme and identified patients with newly diagnosed type 2 diabetes from 2001, 2005, and 2009; a new prescription guideline for diabetes care was introduced in 2006. Physician service volume was measured by the number of total outpatients with diabetes. The outcome variable indicated whether a patient was receiving metformin, the guideline-recommended antihyperglycemic agent, at the index date.

Patients visiting physicians who had high or medium volumes of patients with diabetes were more likely to receive metformin than patients visiting physicians who had low volumes; the odds ratios (ORs) were 2.48 (95% CI, 2.03-3.04) and 1.76 (95% CI, 1.45-2.13), respectively. Patients with newly diagnosed diabetes in 2009 and 2005 were more likely to receive metformin than their counterparts in 2001, with ORs of 12.00 (95% CI, 11.19-12.86) and 2.44 (95% CI, 2.30-2.59), respectively. We also found that patients who visited younger physicians, physicians with fewer practice years, physicians practicing in large-scale hospitals, or physicians practicing in urban areas were more likely to receive metformin than their counterparts.

In the process of implementing a new practice guideline for treating patients with diabetes, physicians with higher patient volumes are more likely to adhere to the guideline recommendation.