Boston, MA - It might seem obvious, at least in the US, that acquiring health insurance would improve one's health, but where are the data? Randomized trials not being feasible, a longitudinal analysis based on a nationally representative sample of Americans pointed to a steeper decline in health status in the years before age 65 among the uninsured, compared with those with health insurance; the study was published in the December 26, 2007 issue of the Journal of the American Medical Association [1]. It also suggested that the drop in the uninsured's health started to reverse once Medicare coverage kicked in at 65; the health of the previously insured, however, continued to decline.

"By age 70, the difference in health between the two groups was about half what would be expected in the absence of Medicare coverage," lead author Dr J Michael McWilliams (Harvard Medical School, Boston, MA) told heartwire. "The benefit from gaining health insurance was almost entirely concentrated among those with hypertension, diabetes, heart disease, or stroke."

The analysis prospectively focused on the risk of CV diseases because they are prevalent in older age, many treatments are available, and untreated they can be devastating, McWilliams said. "So these are conditions for which coverage might be particularly important."

The findings provide some of the strongest evidence yet that extending health-insurance coverage to the uninsured would indeed improve their health.

McWilliams said the findings "provide some of the strongest evidence yet that extending health-insurance coverage to the uninsured would indeed improve their health." There seems to be a national consensus that health coverage is important, he observed, yet there are about 47 million Americans, about 16% of the country's population, who don't have it.

He and his colleagues followed the self-reported health status, beginning at age 55, of 5006 people who were continuously insured and 2227 who were at least temporarily uninsured, all participants in the longitudinal Health and Retirement Study. Survey questions tracked changes in general health, mobility, pain, signs of depression, and outcomes related to cardiovascular disease and diabetes.

Of the more than 4400 persons in the analysis who reported a diagnosis of hypertension, heart disease, stroke, or diabetes prior to age 65, two-thirds were insured and one-third were uninsured. According to McWilliams, for every 100 uninsured persons with CV disease or diabetes prior to Medicare eligibility, there were 10 fewer events such as MI or hospitalization for heart failure during the first seven years of Medicare coverage compared with what would have been expected without the coverage.

The analysis controlled for the many significant baseline differences between the previously insured and uninsured cohorts; for example, the latter were more likely to be female, "non-Hispanic black," and smokers, to have less education and income, and not to be employed full time.

The findings provide "compelling evidence of the benefits of Medicare coverage on a range of health outcomes for previously uninsured adults," the group writes. "Proposals to extend insurance coverage to uninsured near-elderly adults have been introduced in the US Congress and endorsed by the American College of Physicians. Providing earlier health insurance coverage for uninsured adults, particularly those with cardiovascular disease or diabetes, may have considerable social and economic value for the United States by improving health outcomes."