Florida seeks high hospital volumes for percutaneous transluminal coronary angioplasty (PTCA) by enforcing certificate of need (CON) laws, whereas California has no such laws. This study compares the volume-outcome relation for PTCA in Florida and California.

The relation between the number of PTCA procedures performed at hospitals and the rate of inhospital bypass graft surgery and death for 292,457 patients in Florida and 390,880 patients in California between 1988 and 1998 was examined with descriptive statistics and logistic regressions.

In 1988, the mean hospital PTCA volumes in Florida (237) and California (218) were not significantly different (P = .44). By 1998, Florida hospital volumes were significantly larger (724 vs 389, P <.001). Logistic regressions indicate that higher log (volume) was associated with lower mortality and urgent bypass grafting rates in both Florida and California during the sample period. Regression estimates indicate that a California hospital with the mean 1998 PTCA volume of 389 procedures had a predicted inpatient mortality rate of 1.4% and urgent bypass grafting rate of 2.2%. If the PTCA volume was raised to the 1998 Florida mean of 724 procedures, the inpatient mortality rate would not fall, although urgent bypass grafting rates were predicted to fall to 2.0%.

Florida CON laws were associated with higher average PTCA volumes relative to California hospitals, where no such laws exist. Because a higher PTCA volume was associated with moderately better outcomes, CON may be marginally effective in improving outcomes for PTCA. Future studies should revisit this hypothesis with data from several states.