Association between nocturia and falls-related long-term mortality risk in the elderly

Objectives: A high falls-related mortality rate in the elderly is not exclusively related to injuries. Moreover, the risk of falls increases with urinary disorders such as nocturia. The aim of this study was to investigate the role of nocturia in falls-related long-term mortality in elderly subjects.

Design: Longitudinal study.

Setting and participants: The "Osservatorio Geriatrico Regione Campania" was a cross-sectional study performed in 1992 in Campania, a region of Southern Italy.

Main measurements: Long-term mortality (12 years' follow-up) in 178 elderly subjects (mean age 74.0 ± 6.3 years) with falls and 1110 elderly subjects (mean age 75.2 ± 6.4 years) without falls at baseline was measured. Subjects were then stratified for the presence/absence of nocturia.

Key results: In our sample, the prevalence of falls was 13.8% and the prevalence of nocturia was 45.7%. Long-term mortality was 51.3% in nonfallers and 62.9% in fallers (P < .05). In the absence of nocturia, long-term mortality was similar in nonfallers and fallers (49.0% vs 46.7%; P = .514, NS). In contrast, in the presence of nocturia, long-term mortality was higher in fallers than in nonfallers (74.5% vs 53.6%; P < .05). Cox regression analysis confirmed the predictive role of falls on long-term mortality in the presence of nocturia (hazard ratio 60; 95% confidence interval 1.01-2.57; P < .05) but not in the absence of nocturia (hazard ratio = 1.27; 95% confidence interval 0.81-1.99; P = .28).

Conclusions: Our data suggest that falls are related to an increased risk of long-term mortality in the elderly much more in the presence of nocturia. This phenomenon is probably related to the high comorbidity that usually affects elderly subjects with nocturia.