Pure stress leakage symptomatology: is it safe to discount detrusor instability?

To determine whether the combination of a urological history and urinary diary, with rigorous selection criteria, can be used to define a group of women on whom urodynamic assessment is unnecessary prior to offering surgery for urinary stress incontinence.

Retrospective review of the urodynamic records of women attending for assessment between January 1992 and December 1996.

Urodynamic Department, Southmead Hospital, Bristol.

5193 women who attended the urodynamic clinic during the five year study period.

Self-completion of a urinary diary in the preceding week before urodynamic assessment and a detailed urological history before undergoing cystometry by all women in the study period. Data were entered onto a computer database. Women reporting stress incontinence in the absence of bladder filling symptoms, with a normal urinary diary showing daytime frequency of seven times or less and nocturia of no more than once, had the results of their filling cystometry analysed.

Of 5193 women, 555 had symptoms of pure stress incontinence and a normal urinary diary. Incontinence was confirmed objectively in 81%, with 9% having incontinence secondary to detrusor instability; 5% had detrusor instability as the sole cause of their incontinence with 4% having a mixed picture of detrusor instability incontinence and urethral sphincter weakness.

Genuine stress incontinence cannot be diagnosed reliably from a urological history, even when rigorous selection criteria are used in combination with a normal urinary diary. Without cystometry, incontinence secondary to detrusor instability will be missed.