Diagnostic Performances of Patient's Interview, Uroflowmetry Alone and Uroflowmetry Paired With Electromyography as Screening Tools to Identify Straining to Void.

Abstract

Aims: To assess the diagnostic performances of patient's interview, final uroflowmetry alone and final uroflowmetry paired with rectus abdominis muscle electromyography (EMG) as screening tools to identify straining to void.

Methods: All consecutive patients who underwent a multi-channel urodynamic study to explore filling phase disorders - including final uroflowmetry associated with intrarectal pressure monitoring - between 2020 and 2021 in our department of urology were considered eligible. Intrarectal pressure curves (gold-standard) were examined by two senior urologists and a continence nurse to determine by consensus the presence of straining to void. The final uroflowmetry curves and final uroflowmetry paired with EMG curves were retrospectively submitted for interpretation to 3 groups of urologists with different levels of experience (residents, fellows, seniors). Each group was composed of 3 independent examiners blinded to intrarectal pressure. The diagnostic performances of patient's interview, and the diagnostic performances as well as the inter- and the intra-examiner correlation of final uroflowmetry alone and final uroflowmetry paired with EMG were assessed.

Results: Overall, 282 neurogenic and non-neurogenic patients were included in the present study. The patient's impression to identify straining to void was associated with a sensitivity, a specificity, a predictive positive value (PPV) and a negative predictive value (NPV) of 68.4%, 63.9%, 68.0% and 64.3%, respectively. Final uroflowmetry alone was associated with a sensitivity, a specificity, a PPV and a NPV of 60.4%, 75.1%, 73.1% and 62.8%, respectively. Final uroflowmetry paired with EMG was associated with a sensitivity, a specificity, a PPV and a NPV of 61.3%, 84.9%, 81.6% and 66.8%, respectively. The inter- and intra-examiner agreement of final uroflowmetry alone was reported as moderate to poor, ranging between 0.17 and 0.72 and 0.58-0.79, respectively. The inter- and intra-examiner agreement of final uroflowmetry paired with electromyography was reported as moderate to poor, ranging between 0.26 and 0.73 and 0.59-0.81, respectively.

Conclusion: Patient's interview, final uroflowmetry alone and paired with rectus abdominis muscle EMG, are not reliable enough to be considered as screening tools for straining to void.