Objective: This study was undertaken to develop a comprehensive risk-assessment approach capable of evaluating maternal and fetal outcomes.
Study design: Data from 10,984 women and 11,066 infants delivered at 79 military treatment facilities in the United States from 1995 to 1997 were used to develop two individual but complementary risk-adjustment models for maternal and, separately, fetal outcomes. A range of maternal and delivery-related risk variables and clinically important outcomes were identified by expert opinion and selected and weighted with ordinal logistic regression analysis. Receiver operating characteristic curves for the maternal and fetal models were determined. Variation across the facilities in risk-adjusted performance was also evaluated.
Results: Risk factors and poor outcomes were rare for both mothers and infants, with 96.9% of infants and 97.7% of mothers having good or excellent outcomes (0.7% mortality and 0.01% mortality, respectively). Despite the low frequency of poor outcomes both models performed well, with receiver operating characteristic curves of 0.75 for maternal outcomes and 0.78 for infant outcomes. When the models were applied to the military treatment facilities, there were significant differences among facilities in risk-adjusted outcomes. Twenty-four of the facilities in the study (30%) had outcomes odds ratios that were significantly >1 or significantly <1 (P <.05). There did not appear to be any relationship between the performance of a military treatment facility for maternal outcome and that for infant outcome.
Conclusion: Complementary risk models for maternal and infant outcomes were developed that had satisfactory discriminatory power across a variety of facilities within a large health system. With further development and refinement this approach holds promise of being able to detect variations in risk-adjusted performance that could be used to identify best practices. The results might also be used to help coordinate and improve the quality of care for the entire conception-to-delivery process.