The External Validation of a Multivariable Prediction Model for Recurrent Pelvic Organ Prolapse After Native Tissue...

Background/Objectives: A prediction model for anatomical cystocele recurrence after native tissue repair was developed and internally validated in 2016. This model estimates a patients' individual risk of recurrence and can be used for counseling. Before implementation in urogynecological clinical practice, external validation is needed. The aim of this study was to assess the external validity of this previously developed prediction model. The secondary aim was to test the performance of this model with a composite and subjective outcome of pelvic organ prolapse (POP) recurrence. Furthermore, the aim was to investigate whether risk factors for POP recurrence were in line with the population in which the original model was developed. Methods: In this prospective multicenter cohort study, 246 patients who underwent anterior colporrhaphy were included. Inclusion criteria were patients scheduled to undergo a primary anterior colporrhaphy (with a POP Quantification (POPQ) stage ≥ 2 cystocele). A combination of a primary anterior colporrhaphy with other POP or incontinence surgery (without the use of vaginal or abdominal mesh material) was permitted. Patients with prolapse or incontinence surgery prior to index surgery could not participate. All patients filled in questionnaires, pelvic floor ultrasound was performed preoperatively, and data from the medical file concerning POPQ stage and obstetric and general history were obtained. Results: Thirty women (12.2%) were lost at follow up. Anatomical cystocele recurrence was present in 107/216 (49.5%), subjective recurrence in 19/208 (9.1%), and 39/219 (17.8%) patients met the criteria for composite outcome. The area under the receiver operating characteristic curves for anatomical, composite, and subjective recurrence were 65.5% (95% CI: 58.7-72.4), 55.8% (95% CI 47.3-64.3%, NS), and 55.1% (95% CI 45.1-65.2%), respectively. In the multivariable analysis, preoperative cystocele stage 3 or 4 and a complete levator defect on ultrasound were independent risk factors for anatomical recurrence. For composite recurrence, younger age and an active employment status were only risk factors in univariable analysis. No significant risk factors for subjective recurrence could be identified. Conclusions: This external validation study showed a moderate performance for a prediction model for anatomical recurrence. The model cannot be used for a composite or subjective outcome prediction because of poor performance. For composite and subjective recurrence, new prediction models need to be developed.