Labor induction rate variation in upstate New York: what is the difference?

Abstract

Background: Labor induction rates in the United States rose from 9.0 percent in 1989 to 20.5 percent in 2001, but reasons for the increase are poorly defined. A birth database from a region of upstate New York, including 31,352 deliveries from 1998 through 1999, was used to determine the degree of variation of labor induction rates among hospitals and practitioners.

Methods: Total and elective labor induction rates were calculated for 16 hospitals and individual staff, and then evaluated using chi-square testing and regression.

Results: Using all laboring women as the denominator, the regional labor induction rate was 20.8 percent; of these inductions, 25 percent had no apparent medical indication. Total induction rates and percent of elective inductions that were elective varied significantly among hospitals (10%-39% and 12%-55%, respectively, p<0.0001) and among practitioners within hospitals (7%-48% and 3%-76%, respectively, p<0.0001). Hospitals varied in size, risk status, and cesarean section rates, but these factors did not correlate with induction rates.

Conclusions: Labor induction rates are highly variable among and within hospitals. Delivery volume, population risk status, and differences in cesarean section rates did not explain this variation.