REGIONALIZATION OF CARDIAC-SURGERY IN THE UNITED-STATES AND CANADA - GEOGRAPHIC ACCESS, CHOICE, AND OUTCOMES

Objective.-To determine how regionalization of facilities for coronary artery bypass surgery (CABS) affects geographic access to CABS and su rgical outcomes.Design.-Computerized hospital discharge records were u sed to measure hospital CABS volume and in-hospital post-CABS mortalit y rates. Relationships between surgical volume and age- and sex-adjust ed mortality rates were compared using chi(2) tests. Small-area analys is of the association between CABS rates and distances to nearest CABS hospital was performed using multivariate linear regression methods. Setting.-All nonfederal hospitals in New York, California, Ontario, Ma nitoba, and British Columbia. Patients.-All adult residents of the fiv e jurisdictions who underwent CABS in a hospital in their jurisdiction from 1987 through 1989. Results.-In New York and Canada, approximatel y 60% of all CABS operations took place in hospitals performing 500 or more CABS operations per year, compared with only 26% in California. The highest mortality rates were found among California hospitals perf orming fewer than 100 CABS operations per year (adjusted 14-day in-hos pital mortality was 4.7% compared with 2.4% in high-volume California hospitals, P<.001). The percentage of the population residing within 2 5 miles of a CABS hospital was 98% in California, 82% in New York, and less than 60% in Canada. Eliminating very low-volume ((100 cases per year) CABS hospitals in California would increase travel distances to a CABS hospital only slightly for a small number of residents. The Can adian degree of regionalization was not associated with lower CABS rat es within provinces for populations living at more remote distances fr om the nearest CABS hospital. Conclusion.-Regionalization of CABS faci lities in New York and Canada largely avoids the problem of low-volume outlier hospitals with high postoperative mortality rates found in Ca lifornia. New York has avoided the redundancy of facilities that exist s in California while still providing residents a geographically conve nient selection of CABS hospitals. Stricter regionalization in Canada may leave residents with a more narrow choice of facilities, but does not disproportionately affect access to surgery for populations living at remote distances from CABS facilities.