Prediction of detrusor underactivity based on non-invasive functional tests and clinical data in patients with symptoms of bladder outlet obstruction.

Abstract

Detrusor underactivity (DU) is a common but relatively under-researched bladder dysfunction. Recently, there has been renewed interest in this topic. The aim of the study was to develop a decision-making algorithm to predict the impaired detrusor contractility in patients with LUTS (lower urinary tract symptoms). A retrospective analysis covered 96 consecutive patients (aged 63 ± 8 years) treated pharmacologically for 50 ± 37 months due to LUTS (persisting for 64 ± 41 months). Functional tests included uroflowmetry and flow cystometry. Weakened detrusor functioning was detected in 58 (60.4%) patients. Decision-making algorithm that included uroflowmetry, flow cystometry and clinical data, was showed to allow to diagnose impaired detrusor function with accuracy of 73% (95% CI - confidence interval: 61-83%) and specificity of 76% (95% CI: 54-90%). The positive predictive value of the classification tree graph is equal to 90% (95% CI: 78 -96%) and the negative predictive value is 50% (95% CI: 34-66%). The weakened detrusor function was more frequent in patients with: time to reach maximum flow rate higher than 13.5 s; time to reach maximum flow rate lower than 13.5 s and mean flow ratio higher than 4.5 ml/s, but time of flow longer than 44.5 s; time to reach maximum flow rate lower than 13.5 s and mean flow ratio lower than 4.5 ml/s, but time of flow longer than 52.5 s. The results of the uroflowmetry can be used to predict the impaired detrusor contractility in patients with LUTS.