An Instrumental Variable Analysis of the Impact of Practice Guidelines on Improving Quality of Care and Diabetes-Related Outcomes in the Elderly Medicare Population
Restricted accessResearch articleFirst published online May, 2008
An Instrumental Variable Analysis of the Impact of Practice Guidelines on Improving Quality of Care and Diabetes-Related Outcomes in the Elderly Medicare Population
The effect of the diabetes practice guideline recommending ≥2 HbA1c tests annually on diabetes-related outcomes was evaluated using Medicare claims data. The study population included 1998 and 1999 incident diabetes patients aged ≥ 67 years, who were Medicare eligible and without known diabetes-related complications at baseline. Number of HbA1c tests was measured 1 year after diabetes incidence. All-cause death and diabetes complications were identified during follow-up, through December 2003. The analysis was conducted with an instrumental variable method and a bivariate probit model, controlling for individual, social, and health care system characteristics. Among 13 033 patients, 27.1% followed the practice guideline. Receiving ≥2 HbA1c tests annually was significantly associated with a decrease in probability of 28.8 percentage points for macrovascular complications, 28.7 for atherosclerotic heart disease, and 23.1 for chronic kidney disease or end-stage renal disease in the 4-year follow-up period. (Am J Med Qual 2008;23: 222-230)
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