Is urodynamics necessary to identify occult stress urinary incontinence?

Purpose: To investigate Occult Stress Urinary Incontinence (OSUI) using physical exam (PE) and urodynamics (UDS) in women with advanced pelvic organ prolapse (POP), and compare the two methods.
Methods: This study comprised 105 women with POP stage-III and -IV, according to POP quantification (POP-Q) system, evaluated prospectively between January and December 2015. A standard history, an incontinence questionnaire and PE were completed before the investigation of the OSUI that was performed in the supine and standing positions, reducing the prolapse using gauze and Cheron dressing forceps. The stress test was performed with and without the prolapse reduction.
Results: The mean patient age was 65.7 years, mean parity 5.1 and mean body mass index 27.4. From a total of 105 patients, 70 (66.7%) presented with POP-Q stage III and 35 (33.3%) stage IV. Sixty-three (60%) women were identified as having OSUI, 27 (25.7%) as continent, and 15 (14.3%) having stress urinary incontinence. From the 63 OSUI subjects, 48 (76.2%) were identified in both evaluations, eight were identified only during PE, and seven only during UDS. The sensitivity to detect OSUI during PE and UDS was 88.9 and 87.3%, respectively (P = .783). The kappa value to measure the agreement between both tests was .648 (95% CI .441-.854).
Conclusion: UDS and PE are equivalent and concordant to demonstrate OSUI, thus it is not necessary to perform UDS to exclusively identify OSUI. UDS utility in OSUI patients, to evaluate urethral and detrusor function, deserves further investigation.