The association of nocturia with incident falls in an elderly community-dwelling cohort

Abstract

Objective: The aim of this study was to examine the association of nocturia with incident falls in a population-based sample of community-dwelling elderly persons.

Methods: The University of Alabama at Birmingham Study of Aging is a prospective cohort study of 1000 community-dwelling older adults in the USA designed to examine factors associated with impaired mobility. Subjects were recruited from a stratified, random sample of Medicare beneficiaries to include equal numbers of black women, black men, white women and white men. Nocturia was assessed at baseline and falls were assessed at baseline and every 6 months for a total of 36 months of follow-up.

Results: A total of 692 individuals (mean age 74.5 +/- 6.2, 48% female, 52% black) did not fall in the 12 months prior to baseline. Of these 692, 214 (30.9%) reported falling at least once during the subsequent 3 years. In unadjusted analysis, three or more nightly episodes of nocturia were associated with an incident fall [RR = 1.27, 95% CI (1.01-1.60)]. After multivariable logistic regression, three or more episodes of nocturia were associated with an increased risk of falling [RR = 1.28, (1.02-1.59)].

Discussion: In a racially diverse, community-based sample of older men and women who had not fallen in the previous year, nocturia three or more times a night was associated in multivariable analysis with a 28% increased risk of an incident fall within 3 years. While this study has several advantages over previous reports (longitudinal follow-up, performance-based measures of function, population-based sampling), causality cannot be ascertained. Further research is needed to ascertain the impact of treatments to reduce nocturia as part of a multi-component programme to reduce fall risk.

Figure 1

Nocturia variable – Relative risk for falling associated with increasing frequency of nocturia compared to those with no nocturia