Association between percutaneous transluminal coronary angioplasty volumesand outcomes in the healthcare cost and utilization project 1993-1994

Studies from a variety of settings have indicated that outcomes for coronar y angioplasty are improved when performed in institutions with high caseloa ds (>400/year). The purpose of this investigation was to examine the volume outcome hypothesis for coronary angioplasty in a 20% stratified sample of acute care, nonfederal hospitals in 17 stares. Data were derived from the N ationwide Inpatient Sample from the Health Care Cost and Utilization Projec t releases 2 and 3, From these records, 163,527 angioplasties from 214 hosp itals were selected. Outcomes included hospital mortality, same-admission c oronary artery bypass surgery, and a combined end point of either death or same-admission surgery, or both. Hospital volumes were defined as low (less than or equal to 200 cases/year), medium (201 to 400), and high (>400), An alyses were conducted separately for patients with and without a principal discharge diagnosis of acute myocardial infarction (AMI), For both AMI and no-AMI groups, the rates of adverse outcomes were generally lower in high-v olume institutions, and this finding was true in both univariate and multiv ariate analyses. Although 27% of hospitals were in the low-volume category, only 5% of all procedures were performed in these institutions. Projecting to all United States hospitals for the 2 years, if all procedures performe d in low-volume centers had been done in high-volume institutions, 137 deat hs could have been averted (90 AMIs, 47 no-AMIs) as well as 404 (46 AMIs, 3 58 no-AMIs) same-admission surgeries. The results of this study support the hypothesis that better results are obtained in higher volume institutions, but also show that in 1993 and 1994, relatively few patients had their pro cedures performed in low-volume institutions. (C) 1999 by Excerpta Medico, Inc.