Development and comparison of prognostic scoring systems for surgical closure of genitourinary fistula

The purpose of this study was to test the diagnostic performance of 5 existing classification systems (developed by Lawson, Tafesse, Goh, Waaldijk, and the World Health Organization) and a prognostic scoring system that was derived empirically from our data to predict fistula closure 3 months after surgery.

Women with genitourinary fistula (n = 1274) who received surgical repair services at 11 health facilities in sub-Saharan Africa and Asia were enrolled in a prospective cohort study. Using one-half of the sample, we created multivariate generalized estimating equation models to obtain weighted prognostic scores for components of each existing classification system and the empirically derived scoring system. With the second one-half, we developed receiver operating characteristic curves using the prognostic scores and calculated areas under the curves (AUCs) and 95% confidence intervals (CIs) for each system.

Among existing systems, the scoring systems that represented the World Health Organization, Goh, and Tafesse classifications had the highest predictive accuracy: AUC, 0.63 (95% CI, 0.57-0.68); AUC, 0.62 (95% CI, 0.57-0.68), and AUC, 0.60 (95% CI, 0.55-0.65), respectively. The empirically derived prognostic score achieved similar predictive accuracy (AUC, 0.62; 95% CI, 0.56-0.67); it included significant predictors of closure that are found in the other classification systems, but contained fewer, nonoverlapping components. The differences in AUCs were not statistically significant.

The prognostic values of existing urinary fistula classification systems and the empirically derived score were poor to fair. Further evaluation of the validity and reliability of existing classification systems to predict fistula closure is warranted; consideration should be given to a prognostic score that is evidence-based, simple, and easy to use.