Association between Health Insurance and Health among Adults with Diabetes: Evidence from Medicare.

OBJECTIVES

Gaining Medicare eligibility at age 65 is associated with increased health insurance coverage and reduced medical expenditure risk, but few studies have examined changes in health outcomes among adults with a specific chronic condition. This study assessed the association between Medicare eligibility and health among adults with diabetes.

DESIGN

Regression discontinuity design to test for discontinuities in healthcare outcomes at age 65 when most US adults become eligible for Medicare.

SETTING

National Health Interview Survey, 2006-2016.

PARTICIPANTS

Respondents ages 55 to 74 with diagnosed diabetes (n = 13 455).

MEASUREMENTS

Primary outcome measures included self-reported fair or poor general health status, any functional limitation, overweight, obese, and body mass index. Secondary outcomes included health insurance coverage, healthcare spending burden, and functional limitations by cause and type.

RESULTS

Medicare eligibility was associated with about an 8.0 percentage point reduction in the uninsured rate (95% confidence interval [CI], -9.9 to -6.0 percentage points; P < .001) and declines in high out-of-pocket healthcare expenditures and worry about medical bills. Eligibility was also associated with reductions of about 5.2 [95% CI, -6.9 to -3.6; P < .001] and 4.7 [95% CI, -7.1 to -2.3; P = .001] percentage points in fair or poor health and any functional limitation, respectively. Declines in functional limitations appeared to be driven by reductions in limitations due to diabetes, arthritis, heart problems, and emotional or behavioral problems. Some evidence indicated that Medicare eligibility was associated with a decline in obesity, but estimates were not consistently statistically significant.

CONCLUSION

Expanded health insurance coverage and gains in coverage quality may improve health outcomes among older adults with diabetes. J Am Geriatr Soc 68:388-394, 2020.