When policy makers and researchers consider potential solutions to the problem of uninsurance in the United States, the question of whether health insurance matters to health is often an issue. This question is far more than an academic concern. It is crucial that U.S. health care policy be informed with current and valid evidence on the consequences of uninsurance for health care and health outcomes, especially for the 45.7 million individuals without health insurance.
Some people might think it is obvious that not having health insurance will have adverse consequences for individuals’ health. On the other hand, some people believe that children and adults without health insurance have access to needed health care services at hospital emergency rooms, community health centers, or other safety net facilities offering charity care. And some observers note that there is a solid body of evidence showing that a substantial proportion of U.S. health care expenditures is directed to care that is not effective and may sometimes even be harmful. At least for the insured population, spending more and using more health care services does not always yield better health outcomes or increase life expectancy (Fisher et al., 2003; Fuchs, 2004; Wennberg and Wennberg, 2003; Wennberg et al., 2006).
Is having health insurance essential for gaining access to appropriate health care services? Or is there evidence that the uninsured population receives the health care services necessary to achieve health outcomes comparable to the insured population? This chapter provides a summary of the key findings from the research evidence on the relationships between health insurance and health outcomes that has emerged since the Institute of Medicine (IOM) released its last report on the issue in 2002 (IOM, 2002a). It is based on two systematic reviews of the literature on the consequences of uninsurance for individuals’ health outcomes commissioned by the committee in 2008: one that evaluated the recent evidence pertaining to children and adolescents (Kenney and Howell, 2008) and a second that evaluated the evidence for adults (McWilliams, 2008).1
In 2002, the IOM judged the available evidence to be sufficiently strong and consistent to conclude that uninsured individuals do not receive needed health care services, and they suffer poorer health outcomes, including, for adults, greater risk of premature death (IOM, 2002a,b). Hadley drew similar conclusions in a comprehensive and rigorous literature review conducted shortly thereafter (Hadley, 2003). Freeman and colleagues, who conducted
The commissioned reviews of the research evidence from 2002 to August 2008 on consequences of uninsurance for access and health were (1) Health Consequences of Uninsurance Among Adults in the United States: An Update, by J. Michael McWilliams, M.D., Ph.D., Harvard Medical School; and (2) Health and Access Consequences of Uninsurance Among Children in the United States: An Update, by Genevieve M. Kenney, Ph.D., and Embry Howell, Ph.D., The Urban Institute. Much of the discussion in this chapter is based on these reviews.