Quality Adjustment for Health Care Spending on Chronic Disease: Evidence from Diabetes Treatment, 1999–2009

US health care expenditures reached $2.5 trillion in 2009, representing 17.6 percent of gross domestic product (GDP) and $8,086 per person (US Department of Health and Human Services Centers for Medicare and Medicaid Services 2011). Since health care represents a large and growing share of the economy, and factors such as population aging imply that chronic disease treatment will continue to expand as a share of health expenditures, developing methods for assessing the value of quality improvement for chronic disease spending is of increasing importance for accurately measuring real economic activity. This paper develops a method for assessing the value of quality changes associated with health care for patients living with one important chronic disease, diabetes mellitus, using 11 years of detailed data on spending and quality of care for over 800 patients. We first provide an overview of measurement issues for health care quality, and then present our data, methods, results, and a brief discussion.