Health Insurance Coverage and Health — What the Recent Evidence Tells Us

Health Insurance Coverage and Health — What the Recent Evidence Tells Us

Health Insurance Coverage and Health — What the Recent Evidence Tells Us

substantial discussion about what effects — if any — insurance coverage has on health and mortality. The prospect that the law’s replacement might lead to millions of Americans losing coverage has brought this empirical question into sharp focus. For instance, politicians have recently argued that the number of people with health insurance is not a useful policy metric1 and that no one dies from a lack of access to health care.2 However, assessing the impact of insurance coverage on health is complex: health effects may take a long time to appear, can vary according to insurance benefit design, and are often clouded by confounding factors, since insurance changes usually correlate with other circumstances that also affect health care use and outcomes.

Nonetheless, over the past decade, high-quality studies have shed light on the effects of coverage on care and health. Here, we review and synthesize this evidence, focusing on the most rigorous studies from the past decade on the effects of coverage for nonelderly adults. Previous reviews have provided a thorough discussion of older studies.3 We concentrate on more recent experimental and quasi-experimental studies of the ACA and other expansions of public or private insurance. The effects of coverage probably vary among people, types of plans, and settings, and these studies may not all directly apply to the current policy debate. But as a whole, this body of research (Table 1) offers important insights into how coverage affects health care utilization, disease treatment and outcomes, self-reported health, and mortality.

Financial Protection and the Role of Insurance

Before we assess these effects, it is worth recognizing the role of insurance as a tool for managing financial risk. There is abundant evidence that having health insurance improves financial security. The strongest evidence comes from the Oregon Health Insurance Experiment, a rare randomized, controlled trial of health insurance coverage.31 In that study, people selected by lottery from a Medicaid waiting list experienced major gains in financial well-being as compared with those who were not selected: a $390 average decrease in the amount of medical bills sent to collection and a virtual elimination of catastrophic out-of-pocket expenses.4,8 Studies of other insurance expansions, such as Massachusetts’ 2006 health care reform,7 the ACA’s 2010 “dependent-coverage provision” enabling young adults to stay on a parent’s plan until age 26,6 and the ACA’s 2014 Medicaid expansion,5 have all revealed similar changes, including reduced bill collections and bankruptcies, confirming that insurance coverage reduces the risk of large unpredictable medical costs.

But from a policy perspective, health insurance is viewed differently from most other types of insurance: there is no push, for example, for universal homeowners’ or renters’ insurance subsidized by the federal government. We contend that there are two reasons for this difference. First, policymakers may value publicly subsidized health insurance as an important part of the social safety net that broadly redistributes resources to lower-income populations. Second, policymakers may view health insurance as a tool for achieving the specific policy priority of improved medical care and public health. Evaluating the impact of insurance coverage on health outcomes — and whether these benefits justify the costs of expanding coverage — is our focus.