Simple bladder filling with a cough stress test compared with subtracted cystometry for the diagnosis of urinary incontinence

Our purpose was to compare the diagnostic efficacy of observing urine loss during simple bladder filling (without pressure measurement) and a cough stress test, with multichannel subtracted cystometry.

The urodynamic records of 77 women complaining of urinary incontinence were reviewed. All women had undergone a full evaluation that included a standardized history and physical examination, urinalysis and urine culture, uroflowmetry with measurement of postvoid residual urine, a cough stress test performed during and after simple retrograde bladder filling, and multichannel subtracted cystometry. The results of simple bladder filling and the cough stress test were recorded as "urge incontinence," "stress incontinence,"mixed incontinence," or "incontinence not demonstrated." The subtracted cystometrogram was then performed, and the urodynamic diagnoses were recorded as "detrusor instability," "genuine stress incontinence," "mixed incontinence," or "incontinence not demonstrated." The records were reviewed, and the results of simple bladder filling with a cough stress test were compared with those obtained by subtracted multichannel provocative cystometry.

With the subtracted multichannel cystometrogram used as the "gold standard" for diagnosis, the demonstration of "urge incontinence" during simple bladder filling had a sensitivity of 64% and a specificity of 86.8% for the demonstration of detrusor instability during cystometry, with a positive predictive value of 83.3% and a negative predictive value of 70.2%. The demonstration of "stress incontinence" during simple bladder filling had a sensitivity of 88.1% and a specificity of 77.1% for the demonstration of "genuine" stress incontinence during cystometry, with a positive predictive value of 82% and a negative predictive value of 84.4%.

The demonstration of urge incontinence during simple bladder filling is a reliable predictor of detrusor instability, but its absence is less reliable in excluding detrusor overactivity as a cause of urinary incontinence. Similarly, the clinical demonstration of stress incontinence during simple bladder filling is predictive of the presence of "genuine" stress incontinence during subtracted multichannel provocative cystometry. The inability to demonstrate stress incontinence during simple bladder filling is highly correlated with the absence of "genuine" stress incontinence during complex urodynamic testing. Simple bladder filling is a reliable method of diagnosing urinary incontinence. In many cases it can replace complex urodynamic testing, particularly if the proposed treatment for the condition carries a low level of risk, and is helpful in selecting patients who need more extensive evaluation.