The trade-off between costs and outcomes: the case of acute myocardial infarction

To investigate and to quantify the relationship between hospital costs and health outcomes for patients with acute myocardial infarction (AMI) in Veterans Health Administration (VHA) hospitals using individual-level data for costs and outcomes.

VHA administrative files for the fiscal years 2000-2006.

Costs were defined as costs incurred during the index hospitalization for treatment of AMI. Mortality and readmission, assessed 1 year after the index hospitalization, were used as measures of clinical outcome. We examined health outcomes as a function of costs and other patient-level and hospital-level characteristics using a two-stage Cox proportional hazard model that accounted for competing risks within a multilevel framework. To control for patient comorbidities, we compiled a comprehensive list of comorbidities that have been found in other studies to affect mortality and readmissions.

We found that costs were negatively associated with mortality and readmissions. Every U.S.$100 less spent is associated with a 0.63 percent increase in the hazard of dying and a 1.24 percent increase in the hazard to be readmitted conditional on not dying. This main finding remained unchanged after a number of sensitivity checks.

Our results suggest that there is a trade-off between costs and outcomes. The negative association between costs and mortality suggests that outcomes should be monitored closely when introducing cost-containment programs. Additional studies are needed to examine the cost-outcome relationship for conditions other than AMI to see whether our results are consistent.