The case-control population was restricted to women with complete cost data for the original surgical admission and any hospital readmission(s) within 30 days after low transverse cesarean delivery, and included 80 women with SSI, 121 women with endometritis, and 309 control patients without infection. Nineteen women had both SSI and endometritis.
Separate GLS models were created to determine the impact of SSI and endometritis on hospital costs using the two sources of data (administrative or medical record) to identify covariates. In the administrative data model, covariates associated with significantly increased costs were young age, severe complications of delivery, pneumonia, pulmonary collapse or insufficiencies, pre-eclampsia/eclampsia, chorioamnionitis, maternal cardiac conditions, sexually transmitted infection, obstetric laceration and/or trauma, ovarian procedures, and placement of a central venous catheter. In the alternative model using medical record data, covariates associated with significantly increased costs included age, non-Caucasian race, labor induction, use of drains, additional surgical procedure other than bilateral tubal ligation, transfusion and/or anemia, severe pre-eclampsia/eclampsia, general anesthesia, inhaled steroids, preoperative antibiotics for therapy of chorioamnionitis, and postoperative hematoma. The attributable costs of SSI and endometritis estimated by the two multivariate GLS regression models were very similar, regardless of the source of data used to specify covariates (Table).