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?H₂O in urodynamic stress incontinence (USI), 50?cm?H₂O in mixed urinary incontinence (MUI), 65?cm?H₂O in detrusor overactivity incontinence (DOI) and 67?cm?H₂O 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?H₂O 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.