Context Uninsured adults receive less appropriate care and have more adverse
health consequences than insured adults. Longitudinal studies would help to
more clearly define the effects of health insurance on health care and health.
Objective To assess the differential effects of gaining Medicare coverage on use
of basic clinical services and medications by previously insured and uninsured
Design and Setting Household survey data from the nationally representative Health and
Retirement Study were used to analyze differences in receipt of basic clinical
services by adults in 1996 and 2000, before and after becoming eligible for
Medicare at age 65 years.
Participants A total of 2203 adults aged 60 to 64 years in 1996 who were classified
as continuously uninsured (n = 167), intermittently uninsured (n = 216), or
continuously insured (n = 1820) in 1994 and 1996, prior to Medicare eligibility.
Main Outcome Measures Individuals' reports of receiving cholesterol testing, mammography (in
women), prostate examination (in men), and treatment of arthritis and hypertension
in the prior 2 years.
Results The difference in cholesterol testing between continuously insured and
continuously uninsured adults was significantly reduced after Medicare eligibility
(35.4% vs 17.7%; change of −17.7% [95% CI, −29.3% to −6.2%]; P = .003), and the reduction was substantially greater
among those with hypertension or diabetes than among other adults (29.2% vs
7.7%; difference of 21.5% [95% CI, 0.2% to 42.9%]; P =
.048). Differences in use were similarly reduced after Medicare eligibility
for mammography in women (30.3% vs 15.0%; change of −15.3% [95% CI,
−29.9% to −0.7%]; P = .04) and prostate
examination in men (45.2% vs 20.0%; change of −25.2% [95% CI, −45.4%
to −5.1%]; P = .01). Continuously uninsured
adults with arthritis reported significantly greater increases in arthritis-related
medical visits and limitations of activity than continuously insured adults
after Medicare eligibility, but not greater increases in arthritis treatments.
Among adults with hypertension, differences in use of antihypertensive medications
between continuously uninsured and insured adults were essentially unchanged
after Medicare coverage.
Conclusions Previously uninsured adults substantially increased their use of covered
basic clinical services but not medications after gaining Medicare coverage.
An affordable option through which near-elderly uninsured adults could purchase
Medicare coverage might have similar effects.