Misdiagnosis of urinary incontinence in nursing home women: prevalence and a proposed solution.

Because of the high prevalence of detrusor hyperactivity with impaired contractility (DHIC) in incontinent institutionalized women, we postulated that: 1) single-channel cystometry, the most commonly used diagnostic test, would be inadequate when used alone but that 2) its accuracy could be greatly enhanced by combining it with a previously-performed stress test. To test the hypothesis, we used blinded comparison of a clinical stress test and single-channel cystometry with multichannel videourodynamic evaluation (criterion standard), a strategy designed a priori. Subjects were 97 incontinent women who were considered representative of incontinent nursing home women nationally. With cystometry alone, 9 of 37 women with DHIC (24%) were misdiagnosed as stress-incontinent vs. 1 of 25 with DH (P = .03). In each case, misdiagnosis was due to failure to recognize low-pressure involuntary bladder contractions. Combining cystometry with the stress test improved diagnostic accuracy markedly. Of the 77% of women in whom the results of both tests were congruent, all were correctly classified. When results of the two tests were discordant, neither was superior. Significantly, no woman with stress incontinence was missed by the two-test strategy, nor was anyone with detrusor hyperactivity misclassified. We conclude that in institutionalized elderly women, DHIC commonly mimics other types of urinary tract dysfunction. Thus, single-channel cystometry alone is an inadequate diagnostic test in this population. However, a strategy that combines cystometry with a clinical stress test can correctly classify the majority of such women and identify those in whom the diagnosis is less secure. Use of this simple strategy would facilitate correct diagnosis and initial treatment of most institutionalized women without referral, and also enrich the referred population with those most likely to benefit. Such an approach could significantly improve the approach to this costly and morbid condition.