Urinary incontinence and mortality among older adults residing in care homes

Aim: To assess the association between baseline urinary incontinence and long-term, all-cause mortality.

Background: Urinary incontinence is a common disorder among older institutionalised adults, with important consequences for morbidity and quality of life. Moreover, while it is a consistent mortality marker, the extent to which this association might be causal remains controversial.

Design: A cohort study.

Methods: We conducted a mortality follow-up study on a cohort of 675 nursing-home residents in the city of Madrid (Spain), from their 1998-1999 baseline interviews to September 2013. Study subjects or their caregivers were asked whether the resident had experienced any involuntary leakage of urine in the preceding 14 days, with subjects being subsequently defined as continent, mildly incontinent, or severely incontinent. Hazard ratios for all-cause mortality were estimated using Cox proportional hazards models.

Results: After a 4061 person-year follow-up (median/maximum of 4·6/15·2 years), 576 participants had died. In fully-adjusted models, urinary incontinence was associated with a 24 per cent increased risk of all-cause mortality. There was a graded relationship across severity levels, with hazard ratios 7% higher for mild and 44% higher for severe incontinence as compared with the continent group. The adjusted mortality fraction attributable to urinary incontinence was 11 per cent.

Conclusion: It would appear that urinary incontinence is not only a marker but also a real determinant of survival in the institutionalized population. This finding, which seems plausible in a population of frail older adults, warrants further research into mechanisms that could help to elucidate this hypothesis.