The Q-tip test and urethrovesical junction mobility.
OBJECTIVE
To determine the accuracy of the Q-tip test to measure urethrovesical junction mobility.


METHODS
One hundred fourteen women with urinary incontinence or genital prolapse were evaluated with a Q-tip test and perineal ultrasound scanning to measure urethrovesical junction mobility with strain. The sensitivity, specificity, and positive and negative predictive values of the Q-tip test to diagnose urethrovesical junction hypermobility were calculated using ultrasound as the standard. Repeat Q-tip and ultrasound measurements were obtained in ten subjects and analyzed for reproducibility.


RESULTS
The Q-tip test had a sensitivity of 25%, specificity of 78%, positive predictive value of 67%, and negative predictive value of 37%. The Q-tip and ultrasound measurements were reproducible, as the within-subject variation was significantly small when compared to between-subject variation (P = .0001).


CONCLUSIONS
The Q-tip test is inaccurate for measurement of urethrovesical junction mobility and should not be used in the manner described to diagnose urethrovesical junction hypermobility.
Caputo
R M
RM
Department of Obstetrics and Gynecology, Methodist Hospital of Indiana, Indianapolis.
Benson
J T
JT
D005260:Female; D006801:Humans; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D014521:Urethra / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001743:Urinary Bladder / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014549:Urinary Incontinence / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D014596:Uterine Prolapse / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology