Volpp and colleagues assessed mortality rates for insured and uninsured patients hospitalized for acute myocardial infarction in New Jersey before and after state market reforms in 1994 reduced subsidies for hospital care for the uninsured and changed the hospital payment system to price competition from one in which reimbursement was based on costs (Volpp et al., 2003). The research team performed difference-in-differences analyses of New Jersey hospital discharge data, in which discharge data from New York and the Nationwide Inpatient Sample were used to control for secular trends. While not directly addressing the effects of losing or gaining health insurance, this study sheds light on what happens to uninsured patients hospitalized with cardiovascular disease when changes in reimbursement policy restrict hospitals’ ability to recoup the costs of providing care to uninsured adults.
Volpp and his colleagues found no significant changes in mortality from acute myocardial infarction for insured patients in New Jersey in comparison to patients in New York or the nation prior to 1994. In contrast, the absolute mortality rate increased differentially after the reform by 3.7 percent to 5.2 percent for uninsured patients in New Jersey compared to uninsured patients in New York, representing a 41 percent to 57 percent relative increase over their baseline death rate of 9.1 percent before the reform. Concurrent relative decreases in rates of cardiac procedures were also observed for these uninsured patients. These findings provide strong evidence that lack of health insurance coverage exposes uninsured patients with acute myocardial infarction to poorer quality of care and higher mortality risks when providers are reimbursed less for uncompensated care or are unable to use profits from insured patients to cover the costs.
In a similarly designed quasi-experimental analysis of discharge data in New York and New Jersey, Volpp and colleagues found relative increases in mortality for uninsured New Jersey patients admitted for congestive heart failure and stroke when compared to uninsured New York patients with these conditions (Volpp et al., 2005). On the other hand, they found mortality trends during the 1990 to 1996 period to be similar in New Jersey and New York for hospitalized patients with hip fracture, gastrointestinal bleeding, pulmonary embolism, or pneumonia, regardless of the patients’ insurance status.
Card and colleagues, in another quasi-experimental study of state discharge data, assessed the effects of near-universal Medicare coverage after age 65 on mortality among acutely ill patients in California who were hospitalized between 1992 and 2002 (Card et al., 2007). To avoid a nonrepresentative sample of uninsured adults under age 65, the analysis focused on serious acute conditions or acute exacerbations of chronic conditions, including acute myocardial infarction, stroke, respiratory failure, COPD or asthma exacerbation, hip fracture, and seizure. A quasi-experimental analy-