Our objective was to determine whether a positive supine empty stress
test is predictive of a low Valsalva leak point pressure (less than or
equal to 60 cm of water). Evaluation was carried out on 179 patients
with a history of genuine stress incontinence confirmed with urodynami
c testing. All patients had a supine stress test performed after voidi
ng. Residual urine determinations were all <100 cc. A vesical Valsalva
leak point pressure determination (cough and strain) was performed du
ring multichannel urodynamics with 150 cc in the bladder. Urethral pro
filometry was performed at maximum capacity. There was a statistically
significant relationship between a low leak point pressure and a posi
tive supine empty stress test (P < 0.000). The supine empty stress tes
t had a sensitivity of 79% and a specificity of 62.5% for the detectio
n of a low leak point pressure. The negative predictive value was high
at 90%. For the age group 50 years and younger the negative predictiv
e value was 95%. However, there was no significant relationship betwee
n a positive supine empty stress test and a low maximal urethral closu
re pressure. We conclude that the supine empty stress test is a useful
screening test for a low leak point pressure but not a low urethral c
losure pressure. Its high negative predictive value is useful in exclu
ding the presence of a low leak point pressure and may help the clinic
ian to determine which patients with genuine stress incontinence need
further assessment of the dynamic function of the urethral sphincter.
(C) 1998 Wiley-Liss, Inc.