Cross-sectional versus sequential quality indicators of risk factor management in patients with type 2 diabetes.

BACKGROUND The fairness of quality assessment methods is under debate. Quality indicators incorporating the longitudinal nature of care have been advocated but their usefulness in comparison to more commonly used cross-sectional measures is not clear. AIMS To compare cross-sectional and sequential quality indicators for risk factor management in patients with type 2 diabetes. METHODS The study population consisted of 1912 patients who received diabetes care from one of 40 general practitioners in The Netherlands. Clinical outcomes, prescriptions, and demographic data were collected from electronic medical records. Quality was assessed for glycemic, blood pressure, and lipid control using indicators focusing on clinical outcomes, and treatment in relation to outcomes. Indicator results were compared with a reference method based on national guidelines for general practice. RESULTS According to the reference method, 76% of the patients received management as recommended for glycemic control, 58% for blood pressure control, and 67% for lipid control. Cross-sectional indicators looking at patients adequately controlled gave estimates that were 10-25% lower than the reference method. Estimates from indicators focusing on uncontrolled patients receiving treatment were 10-40% higher than the reference method for blood pressure and glycemic control. Sequential indicators focusing on improvement in clinical outcomes or assessing treatment modifications in response to poor control gave results closer to the reference method. CONCLUSIONS Sequential indicators are valuable for estimating quality of risk factor management in patients with diabetes. Such indicators may provide a more accurate and fair judgment than currently used cross-sectional indicators.