HbA1c test: diabetic Medicare beneficiaries (percent)
Percent of diabetic Medicare enrollees ages 65-75 receiving a hemoglobin A1c test in the past year
Number of Medicare fee-for-service enrollees ages 65-75 with diabetes who received the HbA1C test in the past year
Number of Medicare fee-for-service enrollees age 65-75 with a medical visit in the past year with recorded diabetes
Caveats and Limitations
This measure requires access to the Health Care system for patients to be tested and then accurately diagnosed with diabetes. The Centers for Disease Control and Prevention (CDC) estimated in 2007 that in the United States approximately 18 million people had diagnosed diabetes and approximately 6 million people had undiagnosed diabetes. This means that a county could report a high percentage of HbA1c testing, but simultaneously could have a large undiagnosed diabetic population.
- Hemoglobin A1c levels are one measure of glycemic control for persons with diabetes. In general, A1c values exceeding 9% indicate poor glycemic control.
Hemoglobin A1c testing: CPT codes 83036, 86037; CPT II codes 3046F, 3047F.
Diabetes diagnosis: two face-to-face encounters with different dates of service in an ambulatory setting or nonacute inpatient setting or one face-to-face encounter in an acute inpatient or emergency room setting during measurement year or prior year.
Diabetes definition used for numerator and denominator: ICD-9 codes: 250xx, 357.2x, 362.0x, 366.41, 648.0x: DRGs 294, 295; for Q4, MS-DRG codes 637, 638, 639.
Because every diabetic patient in this cohort should receive these tests, regardless of age, sex or race, statistical adjustments to correct for underlying population differences are not relevant.
- Diabetes mellitus: Percent of patients with a diagnosis of diabetes mellitus having hemoglobin A1c HbA1c) greater than 9 or not done during the past year [online]. National Quality Measures Clearinghouse, Agency for Healthcare Research and Quality. Available from:
Dartmouth Atlas of Health Care
The Dartmouth Atlas Project (DAP) began in 1993 as a study of health care markets in the United States, measuring variations in health care resources and their utilization by geographic areas: local hospital market areas, regional referral regions, and states. More recently, the research agenda has expanded to reporting on the resources and utilization among patients at specific hospitals. DAP research uses very large claims databases from the Medicare program and other sources to define where Americans seek care, what kind of care they receive, and to correlate increasing expenditures and the supply of health providers and services with health outcomes.
Data Source Methodology
Indicators are created from Medicare claims and administrative data. The percentage of Medicare deaths occurring in a hospital was computed using “death in a hospital” (discharge status B in the Medicare Provider Analysis and Review (MEDPAR) file) as the numerator event. For the percentage of Medicare deaths who were admitted to an intensive care unit (ICU) in the last 6 months of life, the numerator event was “death in a hospital with admission to an ICU within 6 months of the death date, “ using MEDPAR files. Rates were age, sex, and race adjusted and were expressed as a percentage of deaths. Medicare decedents are identified by their ZIP code of residence. Total ICU days measures intensive care days (which includes medical, surgical, trauma, and burn care) and coronary care days to produce a total ICU days measure. Intermediate care or step-down units are also included.