Maximum urethral closure pressure in women: normative data and evaluation as a diagnostic test.

INTRODUCTION AND HYPOTHESIS: Our goal was to identify correlates of maximum urethral closure pressure (MUCP) and MUCP as a diagnostic test for stress urinary incontinence (SUI).

METHODS: This study was a retrospective review of women with non-neurological referrals for urinary incontinence between1995 and 2006.

RESULTS: We studied the characteristics of 8,644 women who underwent urodynamics for non-neurological referrals. Mean MUCP was 48 cm H(2)O in urodynamic stress incontinence (USI), 50 cm H(2)O in mixed urinary incontinence (MUI), 65 cm H(2)O in detrusor overactivity incontinence (DOI) and 67 cm H(2)O for continent women . Age and MUCP were negatively correlated in all groups. Multiple regression analysis showed lower levels of MUCP in women with USI who also had previous hysterectomy or anti-incontinence surgery or who were in an older age group. Previous anti-incontinence surgery and older age were risk factors for lower MUCP in women with MUI and DOI. Receiver operator curves did not show MUCP to have utility as a diagnostic test despite age and parity stratification. MUCP < 20 cm H(2)O showed a sensitivity of 5 % and specificity of 98 % in diagnosing USI.

CONCLUSIONS: MUCP failed to meet the criteria for a diagnostic test. Women with USI and MUI have lower MUCP than women with DOI and continent women in each decade of life. MUCP decreases with age.