Although Michael Klein and colleagues1 have not established a relation between delivery volume and outcome in obstetrics, we cannot say that no relation exists. Their sample size does not allow enough precision to exclude a clinically meaningful association.
The adjusted odds ratios of 0.908 and 0.849 (high volume v. low volume) for low Apgar score and neonatal intensive care unit/special care unit (NICU/SCU) admissions were not statistically significant, but some might consider such odds ratios clinically significant if they are true. More important, the confidence intervals for these odds ratios were wide and include effects that would certainly be clinically meaningful. In multivariate analysis, there were trends (again not statistically significant) of more episiotomies, cesarean sections and instrument deliveries in the low-volume group.
This study (which included 549 births attended by low-volume physicians) adds to reassuring literature that suggests no association between delivery volume and outcomes. However, the trends favouring higher delivery volume and the relatively rarity of poor neonatal outcomes necessitate a larger sample size to demonstrate that no clinically significant association exists between adverse outcomes and delivery volume.
Erik J. Lindbloom Assistant Professor Michael L. LeFevre Professor University of Missouri-Columbia Department of Family and Community Medicine Columbia, Mo.
Reference
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