Comparison of risk-adjusted 30-day postoperative mortality and morbidity in Department of Veterans Affairs hospitals and selected university medical centers: general surgical operations in women

Abstract

Background: In 1985, Congress mandated that the Department of Veterans Affairs (VA) compare its risk-adjusted surgical results with those in the private sector. The National Surgical Quality Improvement Program was developed as a result, in the VA system, and subsequently trialed in 14 university medical centers in the private sector. This report examines the results of the comparison between patient characteristics and outcomes of female general surgical patients in the two health care environments.

Study design: Preoperative patient characteristics and laboratory variables, operative variables, and unadjusted postoperative outcomes were compared between VA and the private sector populations. In addition, stepwise logistic regression models were developed for 30-day postoperative mortality and morbidity. Finally, the effect of being treated in a VA or private sector hospital was assessed by adding an indicator variable to the models and testing it for statistical significance.

Results: Data from 5,157 female general surgical VA patients who underwent eligible procedures were compared with those from 27,467 patients in the private sector. Unadjusted 30-day mortality was virtually identical in the two groups (1.3%). The unadjusted morbidity rate was slightly, but notably, higher in the private sector (10.9%) as compared with that observed in the VA (8.5%, p < 0.0001). Predictive models were generated for mortality and morbidity combining both groups; top variables in these models were similar to those described previously in the National Surgical Quality Improvement Program. The indicator variable for system of care (VA versus private sector) was not statistically significant in the mortality model, but substantially favored the VA in the morbidity model (odds ratio=0.80, 95% CI=0.71, 0.90).

Conclusions: The data demonstrate that in female general surgical patients, risk-adjusted mortality rates are comparable in the VA and the private sector, but risk-adjusted morbidity is higher in the private sector. Rates of urinary tract infections in the two populations may account for much of the latter difference.