Variation in office-based quality. A claims-based profile of care provided to Medicare patients with diabetes

Abstract

Objectives: To demonstrate that claims data "profiling" can be used as an ongoing method to support ambulatory care quality improvement; to measure the quality of office-based care provided to elderly patients with diabetes in three states; and to identify factors associated with better attainment of quality standards.

Study design: A cross-sectional study based on a 100% sample of the Medicare claims (Part B and Part A) submitted between July 1, 1990, and June 30, 1991.

Setting: All primary care practices (both solo and group) actively seeing Medicare patients with diabetes in Alabama, Iowa, and Maryland (n = 2980).

Patients: All elderly (> or = 65 years) Medicare patients seen by the study physicians and assigned a diagnosis of diabetes (n = 97,388) by any office-based physician during the year.

Main outcome measures: The proportion of patients with diabetes receiving the following procedures (from any provider) at least once during the study period: hemoglobin A1C measurement, ophthalmologic examination, total cholesterol measurement, and blood glucose measurement. We considered the first three services to be optimally recommended and blood glucose measurement to be of limited use.

Results: Based on analyses of services provided in the ambulatory setting, we found that 84% of diabetics did not appear to receive the recommended hemoglobin A1C measurement, 54% did not see an ophthalmologist, and 45% received no cholesterol screening. Practice patterns varied considerably across the three states (up to 2.38-fold), even after adjusting for patient case mix and physician characteristics. Patients of general practitioners were less likely to meet recommended quality criteria than patients of internists or family practitioners. Patients receiving care from rural practitioners were less likely to receive services, either recommended or not, than those in urban locations.

Conclusions: Elderly patients with diabetes do not appear to be receiving optimal care. This study underscores the value of practice guideline development and dissemination in the ambulatory arena. This study provides substantial evidence that existing administrative claims data can be used to support ambulatory quality improvement activities.