Dynamic urethral pressure/ profilometry pressure transmission ratio determinations in stress-incontinent and stress-continent subjects

Bladder-to-urethra pressure transmission ratios were calculated in each quarter (designated Q1 through Q4) of the dynamic urethral pressure profile in 110 subjects. Thirty-seven subjects had genuine stress urinary incontinence, whereas 73 were stress continent. Subjects with genuine stress incontinence had significantly lower mean (± SD) pressure transmission ratios in all four urethral quarters compared with stress-continent subjects: 71% ± 14% versus 94% ± 38% for 01 (p = 0.004), 69% ± 16% versus 101% ± 42% for Q2 (p = 0.00001), 79% ± 19% versus 113% ± 46% for Q3 (p = 0.0001), and 90% ± 22% versus 117% ± 36% for 04 (p = 0.001). A pressure transmission ratio value <90% in the proximal half of the dynamic profile had a sensitivity of 97%, a specificity of 56%, an abnormal predictive value of 53%, and a normal predictive value of 97%. Calculation of pressure transmission ratios, as opposed to declaring the stress profile positive or negative based on whole urethra/bladder pressure equalization with stress, enhances the utility of the dynamic urethral pressure profile and allows quantification of one of the several variable in the equation of stress urinary incontinence. (AM J OBSTET