Wellness in a Heartbeat

 

Health insurance saves lives, boosts self-rated health and financial protection, and lowers the likelihood of depression, a new evidence review has found.

 

The risk for death among the insured, compared with the uninsured, is 0.71 to 0.97, the researchers say.

Steffie Woolhandler, MD, MPH, from the City University of New York School of Urban Public Health at Hunter College, New York City, and David U. Himmelstein, MD, from Harvard Medical School, Boston, Massachusetts, report their findings in an article June 26 in Annals of Internal Medicine.

 

The results strengthen data from a 2002 Institute of Medicine overview of 130 mostly observational studies that found that "the uninsured have poorer health and shortened lives," and that obtaining coverage would reduce their all-cause mortality.

 

The current review included data from randomized controlled trials that differed in quality, mortality follow-ups of population-based health surveys, and quasi-experimental studies of coverage expansions in US states and Canadian provinces.

 

Among several specific conditions examined, the uninsured were less likely to use recommended preventive services and were found to have worse survival.

 

The Oregon Health Insurance Experiment was the only well-conducted randomized controlled trial that analyzed the effect of being without insurance on health outcomes. It included 74,922 nondisabled adults on a waiting list for Medicaid and found that Medicaid coverage lessened mortality by 0.13 percentage points, for an estimated mortality effect of 0.84 for coverage compared with non-coverage.

 

"This difference was not statistically significant, an unsurprising finding given the OHIE's low power to detect mortality effects because of the cohort's low mortality rate, the low dose of insurance, and the short follow-up," the researchers write.

 

The two National Health and Nutrition Examination Study analyses that include physicians' determinations of participants' baseline health found important mortality benefits associated with insurance. One found that the hazard ratio for coverage was 0.8 (P = .05) compared with non-coverage after adjustment for baseline characteristics and health status.

 

In the other, the hazard ratio for coverage was 0.71 (P < .05).

 

In quasi-experimental studies, researchers compared mortality trends in matched locations that did and did not have coverage expansions in the United States, and one in Canada. All of them found that increased coverage was associated with significant reductions in mortality. The two US studies found risk ratios for expansion of 0.939 (P = .001) and 0.971 (P = .003) in states that expanded coverage compared with those that did not. The Canadian study found a 0.95 or 0.96 risk ratio (P < .05 for both) for expansion compared with non-expansion, depending on how the researchers modeled time trends.

 

Several researchers have analyzed data from the longitudinal Health and Retirement Study; most found that near-elderly participants with insurance had slower health decline and decreased mortality.

 

Determining whether lack of insurance ("uninsurance") increases mortality is complicated for several reasons, the researchers write. It is unethical to randomly assign people to uninsurance, and quasi-experimental analyses depend on unverifiable assumptions. Long follow-up is required because deaths are uncommon and make take a long time to occur. In addition, many people go back and forth between insurance and uninsurance, which waters down the effects of uninsurance. Finally, participants' self-reports of baseline health may be influenced by whether they are insured, making statistical adjustments for baseline health difficult.

 

Despite these limitations, the "evidence accumulated since the publication of the [Institute of Medicine's] report in 2002 supports and strengthens its conclusion that health insurance reduces mortality," the researchers explain. "Several newer observational and quasi-experimental studies have found that uninsurance shortens survival, and a few with null results have employed confounded or questionable adjustments for baseline health. The results of the only recent [randomized controlled trial], although far from definitive, are consistent with the positive findings from cohort and quasi-experimental analyses."

 

These results are particularly timely in light of current policy debates regarding healthcare in the United States and whether to repeal the Affordable Care Act, which President Barack Obama signed into law on March 23, 2010.

"Our focus on mortality should not obscure other well-established benefits of health insurance: improved self-rated health, financial protection, and reduced likelihood of depression. Insurance is the gateway to medical care, whose aim is not just saving lives, but also the relief of human suffering," the authors write.

 

"Overall, the case for coverage is strong. Even skeptics who suggest that insurance doesn't improve outcomes seem to vote differently with their feet. As one prominent economist recently asked: 'How many of the people who write such things...choose to just not bother getting their healthcare?'"