Objective: To study the relationship between nocturnal micturition and mortality in an elderly population.
Subjects and methods: All 10 216 members of the Swedish pensioners' association (SPF) in two Swedish counties were asked to participate in a questionnaire survey. The questions concerned the general state of health, occurrence of somatic diseases and symptoms, number of voiding episodes per night, everyday habits and behaviour, and the use of drugs. After 6 years, data on deaths were extracted from the National Register of Deaths at the National Central Bureau of Statistics in Stockholm.
Results: There were 6143 evaluable questionnaires, of which 39.5% were from men. The mean (sd) ages of the men and women participating were 73.0 (6.0) and 72.6 (6.7) years, respectively. During a 54-month period after the questionnaire was completed, 444 of the men and 384 of the women died. The men with three or more nocturnal voiding episodes had a higher death rate, at 1.9 (1.4-2.6) times more than the whole group of men (3.4% vs 1.9% per 6 months; P<0.001), and the corresponding women a death rate 1.3 (0.9-2.0) times higher than all women (1.4% vs 1.1% per 6 months, not significant). In a multiple logistic regression analysis, significant independent correlates of death during the study period were: being 70-79 years vs <70 years (odds ratio, OR, 1.92, 95% CI 1.52-2.43), being >/=80 years vs <70 years (5.14, 3.96-6.68), female gender (0.44, 0.37-0.52), health (1. 81, 1.46-2.25), negative health development (1.70, 1.40-2.06), spasmodic chest pain (1.38, 1.09-1.74), diabetes (1.59, 1.18-2.15), stroke (1.82, 1.12-2.93), and three or more vs two or fewer voiding episodes (1.34, 1.01-1.79).
Conclusion: Elderly people who need to void three or more times per night had a greater mortality rate over a 54-month observation period than those voiding less often.