Table IV.

Use of Medicare Services Beginning at Age 65 By Age and Insurance Status Prior to Age 65

		Difference Relative to Privately Insured
		Adjusted			Adjusted Including Supplemental Insurance and Extra Health Controls
	Mean for Privately Insured	Uninsured Ages 65–66	Uninsured Ages 67–68	Uninsured Ages 69+	Uninsured Ages 65–66	Uninsured Ages 67–68	Uninsured Ages 69+
NHIS-Medicare
Expenditures	4,925.59	−70.79 [704.80]	−1280.95** [660.00]	−595.83 [472.56]	--	--	--
Inpatient Stays	0.20	0.00 [0.04]	0.01 [0.04]	0.03*** [0.03]	--	--	--
Physician Visits	7.29	−2.20*** [0.66]	−2.37*** [0.60]	−1.94*** [0.47]	--	--	--
HRS-Medicare
Expenditures	4,148.46	−682.95* [411.78]	−523.62 [468.08]	1218.20 [834.36]	−599.61 [387.88]	−492.24 [422.26]	1168.16 [782.92]
Inpatient Stays	0.18	0.00 [0.02]	0.04 [0.03]	.10** [0.05]	0.00 [0.02]	0.04 [0.03]	.10** [0.05]
Physician Visits	6.50	−1.73*** [0.33]	−0.97*** [0.37]	0.04 [0.35]	−1.44*** [0.31]	−0.69* [0.37]	0.48 [0.37]

"Publicly Insured" category included but not shown.

Adjusted differences consist of marginal effects from a generalized linear model using a log link and, for expenditures, a gamma distribution and for visit/stay counts, a negative binomial. Standard errors are in brackets. Control variables for adjusted differences include age, gender, marital status, race/ethnicity, education and income categories, health status, dummies for census division, and year effects. Additional control variables in the final column include comorbidities of depression, arthritis, cancer, diabetes, heart problems, high blood pressure, lung disease, or psychiatric problem; ADLs; IADLs; current smoker; and drinking frequency. Supplemental insurance status includes those who reported in the wave after turning 65 having insurance through an employer or former employer, as an individual through a MediGAP plan, or with the government through Medicaid or the Veterans Administration.)

The symbols *, ** and *** denote significance at the 10, 5 and 1% level respectively.

For the NHIS, the sample consists of 33,368 person years (22,405 privately insured, 7,473 publicly insured, 960 uninsured at ages 65 or 66, 817 uninsured at ages 67 or 68, and 1,713 uninsured at ages 69+) who match with Medicare records, were under the age of 65 at the time of the survey, and have non-missing information on survey variables. The analysis also excludes those in an HMO once they enter an HMO and individuals in any year who do not have Part B for any month of the year.

For the HRS, the sample consists of 20,047 person year (14,418 privately insured, 3,015 publicly insured, 862 uninsured at ages 65–66, 653 uninsured at ages 67–68, and 855 uninsured at ages 69+) who match with Medicare records, were under the age of 65 at the time of the survey, and have non-missing information on survey variables. The analysis also excludes those in an HMO once they enter an HMO and individuals in any year who do not have Part B for any month of the year.