Women with pure stress urinary incontinence symptoms assessed by the initial standard evaluation including measurement of post-void residual volume and a stress test: are urodynamic studies still needed?

AIMS: The significance of preoperative urodynamic studies in women with a "clinically-defined pure stress urinary incontinence (SUI) symptom" has been debated in recent years. We evaluated changes of reliability of pure SUI symptoms for prediction of pure urodynamic SUI (USUI) when the assessment of post-void residual (PVR) volume and a stress test, designated as the initial standard evaluation in the NICE and AUA guidelines, were added to the process for the diagnosis of pure SUI symptoms.

METHODS

We reviewed records of 1,019 women aged 30-80 who underwent urodynamic study for incontinence. Criteria for pure SUI symptoms were defined as absence of overactive bladder symptoms and voiding difficulties based on a frequency-volume chart and AUA Symptom Index. We then added assessment of PVR volume and a stress test to the process for clinical diagnosis.

RESULTS

Of subjects, 211 (20.7%) could be classified as having a pure SUI symptom. Of these, only 167 (79.1%) had pure USUI and 33 (15.7%) had detrusor overactivity. Eight (3.8%) had detrusor underactivity/bladder outlet obstruction. Sensitivity and specificity of pure SUI symptoms for pure USUI were 28.6% and 89.9%. Addition of assessment of PVR volume and a stress test resulted in an increase of predictive accuracy of only 3.6%.

CONCLUSIONS

As one-fifth of women with pure SUI symptoms exhibit the pathophysiologies that could affect the surgical outcomes despite additional use of PVR assessment and a stress test in the clinical diagnostic process, urodynamic evaluation is considered necessary before anti-incontinence surgery in this population.