Urinary Symptoms, Mobility Limitation, and Subsequent Falls in Older Adults Across Two Longitudinal Cohorts.

Aims: To examine whether urinary symptoms were associated with subsequent falls according to reported mobility limitation and whether they added meaningful information.

Methods: We analysed the first eligible window for adults aged ≥ 60 years in the English Longitudinal Study of Ageing (ELSA; N = 11,676) and Mexican Health and Aging Study (MHAS; N = 11,071). ELSA assessed generic urinary incontinence over 12 months; MHAS assessed urgency urinary incontinence over 2 years. Mobility was a cohort-specific high-demand walking limitation, and the outcome was any next-wave fall. Modified Poisson RRs, multiple imputation, marginal standardized risks, interaction, and effect modification were used.

Results: With neither urinary symptoms nor mobility limitation as the reference, urinary-only RRs were 1.29 (95% confidence interval [CI] 1.19-1.39) in ELSA and 1.14 (95% CI 1.07-1.22) in MHAS; risk differences were +7.6 and +5.9 percentage points. ELSA showed sub-multiplicative interaction with mobility limitation (ratio 0.80, 95% CI 0.70-0.92) and age attenuation; at ≥ 75 years, the urinary-only RR was 1.03 (95% CI 0.88-1.21). Optimism-corrected ΔAUC was 0.0044 in ELSA and 0.0015 in MHAS.

Conclusions: Urinary symptoms were associated with subsequent falls without reported mobility limitation, but the association was context-dependent. ELSA showed mobility-context and age heterogeneity, and incremental discrimination was small. Urinary symptoms were not supported as a stand-alone or universal fall-screening marker.