Regionalization of Tertiary Care: Impact of Safe Cardiovascular Volumes in Iowa

The outcomes of cardiovascular care for individual patients are known to be better when treatment is provided in hospitals where the volume of such care is greater. We examined the impact of establishing safe volume thresholds on hospitals now performing such procedures in the state of Iowa by analysing the relationship between various volume thresholds and the number of hospitals that would continue to provide the service if the thresholds were enforced. Four procedures performed in hospitals in Iowa in 1990 were studied: coronary artery bypass graft surgery, vascular surgery, cardiac valve surgery, and cardiac catheterization. The analysis was conducted assuming current per capita procedure rates and repeated assuming reduced procedure rates. The study finds that the 12 hospitals now performing coronary artery bypass graft surgery in Iowa could be reduced to two, providers of vascular surgery could be reduced to as low as four from the current 33, the 10 providers of cardiac valve surgery might be reduced to one, and catheterization could be provided at two rather than 22 hospitals.