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 Q1 (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 Q4 (p = 0.001). A pressure transmission ratio value less than 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.