Regionalization of coronary artery bypass surgery. Effects on access.

Coronary artery bypass surgery (CABS) has been regionalized in the province of Ontario since the introduction of the procedure in the 1970s. The authors examined the effect of regionalization on the age-adjusted surgery rates in the 38 counties of southern Ontario and found that county surgical rates were not related to whether the county had a referral center, bordered on a county with a referral center, or did not border on such a county (R2 = 0.019, P = 0.712). In addition, surgical rates were not related to the distance in miles to the nearest referral center (R2 = 0.019, P = 0.440). The authors also examined the relationship between the referral center providing care to the county and surgical rates and found a significant relationship between rates of surgery and referral center regardless of whether a strict rule (R2 = 0.741, P less than 0.0001), a majority rule (R2 = 0.514, P less than 0.0001), or a plurality rule (R2 = 0.497, P less than 0.0001) was used to assign counties to referral centers. The authors conclude that CABS rates are more related to the center serving the county than to the distance of the county from a referral center and discuss this finding in relation to access to care and its impact on costs and quality.