Uroflowmetry in female voiding disturbances

Aims: The clinical validity of uro£owmetry in women is attenuated by lack of absolute normal values. A peak £ow <15 mL/sec and/or residual urine >50 mL with a minimum total bladder volume of 150 mL before voiding (volume voidedþresidual) (method A) and the 10th centile curve of the Liverpool Nomogram (method B) for the maximum urine £ow rate have been identi¢ed as useful discriminants when diagnosing voiding di⁄culties in women. This study compares the two methods and analyses the validity of uro£owmetry in female voiding disturbances. Methods: A total of 348 women underwent a full urogynaecologic work-up. Evaluable results of uro£owmetry (229 with method A and 224 with method B) were analysed and compared in terms of the following clinical variables: age, parity, previous urogynaecologic surgery, prolapse grade, symptoms, postvoid residue, and incontinence.Uro£owmetry results were compared with pressure/£ow study results as indicated by four di¡erent cut-o¡s. Results: The odds ratio that a subject with voiding di⁄culty has abnormal £ow is 3.7 (95% CI, 1.9^7) in the patients analysed with method A and 2.8 (95% CI, 1.6^ 5.2) with method B. A good accordance emerged between the two methods in £owmetry results. Uro£owmetry has a speci¢city of >70% and a sensitivity of 50 to 100% depending on the cut-o¡s. Uro£owmetry results in women can be analysed by using either of the methods. Conclusions: Uro£owmetry has a good speci¢city, a high negative predictive value, and a good diagnostic capacity such as to make it useful as the ¢rst diagnostic approach in urogynaecologic patients.