Prevalence and bother of nocturia, and causes of sleep interruption in a Danish population of men and women aged 60-80 years

OBJECTIVE: To study the prevalence and bother of nocturia, and sleep interruptions in an unselected population of Danish men and women aged 60-80 years.

SUBJECTS AND METHODS: A postal questionnaire was sent to 2000 women and 2000 men aged 60, 65, 70, 75, and 80 years. The population was selected at random from The Danish Civil Registration System, in which every person living in Denmark is identified. The Nocturia, Nocturnal Enuresis and Sleep-interruption Questionnaire (NNES-Q) was used to evaluate nocturia and bother, and sleep interruptions. Nocturia was defined as waking at night to void, according to the International Continence Society definition.

RESULTS: In all, 92% (3664) subjects returned the questionnaire; 71% completed the questionnaire satisfactorily and were included in the study. The prevalence of nocturia increased with age. The overall prevalence of nocturia was 77% and there was no difference between men and women (P = 0.11), but men had slightly more severe nocturia than women. The bother caused by nocturia in men and women increased with the severity of nocturia, and women were slightly more bothered than men when the degree of nocturia was >2 voids/night. Nocturia was the most frequent self-reported reason for waking at night, followed by thirst.

CONCLUSION: The prevalence of nocturia increased with age. There was no difference between the genders in the overall prevalence of nocturia, but nocturia of > or = 2 voids/night was more frequent in men. The degree of bother increased with the severity of nocturia, even after correcting for generic quality of life, and the younger groups were the most bothered. Nocturia was the major reason for waking at night, followed by thirst.