Which women with stress incontinence require urodynamic evaluation?

OBJECTIVE: This study was undertaken to determine the predictive value of t he symptom of stress urinary incontinence and to evaluate the ability of ot her factors suggested by a published Agency for Health Care Policy and Rese arch guideline for the discrimination of patients unlikely to require urody namic testing before surgical management. STUDY DESIGN: We evaluated 950 consecutive women without advanced (stage II [ or IV) pelvic organ prolapse who were referred with symptoms of incontine nce. Incontinence was recorded by means of standard forms and was character ized as "any stress loss" (76.4%), "primarily stress loss" (58.9%), "stress loss only" (29.8%), "stress and urge loss" (52.2%), "urge loss only" (13.8 %), "constant and stress loss" (1.9%), or "constant loss" (2.3%). Other var iables were assessed by means of a standardized history, physical examinati on (including urethral axis determination and stress test), 1-week urinary diary, and postvoid residual volume measurement. A urodynamic diagnosis of pure genuine stress incontinence was used as the criterion standard. Sensit ivity, specificity, and positive and negative predictive values were calcul ated. Logistic regression models incorporating various combinations of stre ss loss only, previous prolapse or incontinence surgery, nocturia, Voiding frequency, urethral hypermobility, and postvoid residual volume <100 mt (th e factors recommended by the Agency for Health Care Policy and Research gui delines), along with age and race as predictors of genuine stress incontine nce, were constructed to evaluate the predictive ability of the guideline i n a subset of 447 patients for whom data on all variables were available. RESULTS: Of the entire population 480 (50.5%) had pure genuine stress incon tinence, 134 (14.1%) had both genuine stress incontinence and detrusor inst ability, 180 (18.9%) had pure detrusor instability, and 40 (4.2%) had intri nsic sphincter deficiency. Fifty-four (5.7%) had normal study results, and 62 (6.5%) had other nonincontinence diagnoses. Among the subjects with symp toms of stress loss only, 10.8% did not have genuine stress incontinence co nfirmed on urodynamic examination. Agency for Health Care Policy and Resear ch guideline criteria had excellent discrimination (C statistic of 0.807) c ompared with the sole criterion of stress urinary incontinence only (C stat istic of 0.574), with a positive predictive value of 85.7%. Only 7.8% of su bjects met all the criteria, however, and 5.7% of these ultimately had a ur odynamic diagnosis of either detrusor instability or normal study result. CONCLUSION: The predictive value of stress symptoms alone was not high enou gh to serve as the basis for surgical management. Agency for Health Care Po licy and Research guidelines improved the predictive Value but were applica ble to only a small subset of patients referred with urinary incontinence.