Diagnostic models for male lower urinary tract symptom management in primary care

Objectives - To develop and independently validate risk-prediction models for three common urological conditions based on a combination of simple, minimally-invasive index tests in men with lower urinary tract symptoms (LUTS) presenting to primary care. Design - A prospective, multicentre, diagnostic accuracy study with independent development and validation cohorts. Setting - 67 general practices in England and Wales. Participants - 601 men presenting to primary care with LUTS: 350 in the development cohort and 251 in the validation cohort. Interventions -Index tests - validated symptom assessment, bladder diary, physical examination, serum prostate specific antigen, uroflowmetry and post-void residual volume estimation. Invasive urodynamic studies provided a diagnostic reference standard. Risk prediction models were developed and validated in independent cohorts. Main outcome measures - Discriminative and calibration performance of the risk prediction models for diagnosing bladder outlet obstruction (BOO), detrusor underactivity (DU) and detrusor overactivity (DO) using the c-index, calibration slope and plot and sensitivity and specificity of the models. Results - The BOO model from the development cohort demonstrated good discriminative performance (optimism-corrected c-index of 0.80). The models derived from the development cohort for DU and DO demonstrated moderate discriminative ability (optimism-corrected c-indices of 0.64 and 0.67 respectively). Similar estimates of c-index were observed for each model within the independent validation cohort (BOO=0.82, DU= 0.63 and DO =0.62).. Conclusions - Using a combination of simple, non-invasive index tests can accurately predict common urological diagnoses in men with LUTS, potentially facilitating earlier initiation of evidence-based treatments and improved management in primary care.