Identifying diabetics in Medicare claims and survey data: implications for health services research

Table 1 Prevalence of Diabetes amongst Adults ages 65 and older in Three National Samples

	NHANES	Linked HRS/A1c	Linked HRS/Medicare	Linked HRS/Medicare/A1c
Self-report	19.1% (16.6-21.6)	21.3% (19.8-22.8)	21.7% (20.4-23.0)	21.2% (19.2-23.2)
Hemoglobin A1c ≥ 6.5	12.2% (10.1-14.3)	13.0% (11.8-14.1)	--	12.6% (10.7-14.4)
Undiagnosed	3.8% (1.8-5.7)	4.2% (3.3-5.2)	--	4.4% (3.2-5.6)
Self-report + undiagnosed	22.9%	25.5%	--	25.6%
Medicare claims	--	--	28.7% (27.1-30.2)	27.3% (25.3-29.2)
Sample size	1,066	3,817	6,101	2,028

Parenthetical entries are 95% confidence intervals.
Undiagnosed diabetes refers to the percentage of cases who self-reported not ever receiving a diabetes diagnosis but met the clinical threshold for diabetes (Ha1c ≥ 6.5).
Sources: 2006 Health and Retirement Study (HRS); 2006 Medicare Beneficiary Annual Summary File; 2005–2006 National Health and Nutrition Examination Survey (NHANES).

ISSN: 1472-6963