Test-retest reliability of the cotton swab (Q-tip) test in the evaluation of the incontinent female.
OBJECTIVE
The objective of this study was to determine the test-retest reliability of the cotton swab test.


METHODS
Prospective, blinded, study of the cotton swab test. Subjects underwent two tests within 2-4 weeks. Agreement between resting angles and straining angles was analyzed using a Wilcoxon signed rank test. Agreement of a positive and negative test result, using 30 degrees as cutoff, was evaluated with McNemar's test and kappa statistic.


RESULTS
Fifty subjects participated. The mean resting angle was 3.16 degrees (-6.0 degrees, 10 degrees) and 3.24 degrees (-5.0 degrees, 10 degrees) on repeat (p = 0.99). The mean straining angle was 34.4 degrees (20 degrees, 50 degrees) and 37.0 degrees (25 degrees, 55 degrees) on repeat (p = 0.14). McNemar's test demonstrated good agreement between observations. As the straining angle approached 30 degrees, the agreement between positive and negative exams was only 57%.


CONCLUSIONS
There is good test-retest reliability of the cotton swab test. When the straining angle is 21-49 degrees, there is poor agreement regarding a positive or negative test result.
Swift
Steven
S
Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC 29425, USA. swifts@musc.edu
Barnes
Derrick
D
Herron
Amanda
A
Goodnight
William
W
D000368:Aged; D032561:Cotton Fiber; D003955:Diagnostic Tests, Routine; D005260:Female; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D016037:Single-Blind Method; D014521:Urethra / Q000503:physiopathology*; D014550:Urinary Incontinence, Stress / Q000175:diagnosis* / Q000503:physiopathology*