Model predicts one-year anal incontinence risk after perineal tears

Researchers used three Swedish health and quality registers to develop a prognostic model for anal incontinence one year after vaginal delivery. The development population comprised 8,909 primiparous women with second- to fourth-degree perineal tears who delivered at ≥34 weeks’ gestation during 2014–2019. Logistic regression evaluated 17 candidate predictors using register data collected at eight weeks postpartum; separate models addressed gas and faecal incontinence.

Seven variables remained in the final anal incontinence model, with a high Wexner score the strongest predictor. Discrimination was AUC 0.78 (95% CI 0.76–0.80) for anal incontinence, defined as gas and/or faecal incontinence; 0.80 (0.77–0.83) for faecal incontinence; and 0.78 (0.76–0.80) for gas incontinence. Calibration was reported as accurate, particularly among women with third-degree tears. Temporal validation in a separate cohort delivering during 2020–2022 yielded an AUC of 0.78 (0.75–0.81).

The model could support postpartum risk assessment in women with perineal tears, but predictive performance does not establish whether its use improves care or outcomes. The available abstract does not provide the complete predictor list, validation cohort size or decision thresholds. Applicability beyond the Swedish register population remains uncertain.