Evaluation of Aa Point and Cotton-Tipped Swab Test as Predictors of Urodynamic Stress Incontinence

Abstract

To compare the predictive abilities of the Aa point of the pelvic organ prolapse quantification examination and the cotton-tipped swab test straining angle to diagnose urodynamic stress incontinence. A case-control study was conducted between June 1997 and February 2003. Cases were defined as patients with urodynamic stress incontinence (n = 352). Controls were patients who also underwent urodynamic testing but who did not have a diagnosis of urodynamic stress incontinence (n = 245). Independent variables were defined as Aa point, Aa point of 0 or greater, straining cotton-tipped swab angle, and straining cotton-tipped swab angle of 30 degrees or greater. Logistic regression estimated the odds ratio of stress incontinence in women based on Aa values and cotton-tipped swab straining angle measurements, controlling for other variables commonly associated with stress incontinence. The mean (+/- standard deviation) age of the cases was 55.9 +/- 13.4 and of controls was 55.3 +/- 14.8, (P = .6). The median parity of the cases was 2 (range 0-10) and of controls, 2 (range 0-9) (P = .7). The Aa point was not associated with a diagnosis of stress incontinence (odds ratio 1.01, 95% confidence interval (CI) 0.83-1.23). The adjusted odds ratios of having an Aa value of 0 or greater was 0.49 (95% CI 0.26-0.92), and of having a cotton-tipped swab angle of 30 degrees or greater was 3.1 (95% CI 1.09-5.07), in a model that adjusted for age, parity, race, and postmenopausal and hormonal replacement status. Aa point is not associated with a diagnosis of stress incontinence. However, a cotton-tipped swab angle of 30 degrees or greater is positively associated with stress incontinence.