Validity and reliability of a questionnaire for evaluating nocturia, nocturnal enuresis and sleep-interruptions in an elderly population.
OBJECTIVE
To validate a new questionnaire evaluating nocturia, nocturnal enuresis and sleep-interruptions in an elderly population of men and women in Denmark.


METHODS
The Nocturia, Nocturnal Enuresis and Sleep-interruption Questionnaire (NNES-Q) emerged from review of the literature and expert consensus. The questionnaire was a subset of a larger questionnaire comprising several domains on health status and voiding. Convergent and discriminatory validity was assessed in an unselected population of 2000 men and 2000 women 60-80 years old. To test reproducibility, 400 respondents were mailed a separate questionnaire 2 weeks apart. A subgroup of men and women with and without nocturia was used for evaluating reliability of number of nocturia episodes.


RESULTS
A total of 2825 (70.6%) filled in the questionnaire. A decrease in health status was correlated with increasing bother (range: -0.25 to -0.36, p<0.001, Spearman's r). These findings indicate acceptable convergent validity. Significant discriminatory validity was proven in separate groups of symptom severity (p<0.0001, Kruskal-Wallis test). Median kappa was 0.70 (range 0.58-0.86) indicating substantial agreement in the retest analysis. Number of nocturia episodes in questionnaires correlated with frequency volume charts (Spearman's rho 0.88; p<0.001).


CONCLUSIONS
These data support that the NNES-Q has a good discriminatory and convergent validity, and is reliable over time. The NNES-Q may be useful in epidemiological studies and may also have a potential in daily clinical work up in patients with nocturia and nocturnal enuresis.
Bing
M H
MH
Department of Obstetrics and Gynaecology, Glostrup Hospital, University of Copenhagen, DK-2600 Glostrup, Denmark.
Moller
L A
LA
Jennum
P
P
Mortensen
S
S
Lose
G
G
D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D053158:Nocturia / Q000150:complications* / Q000453:epidemiology / Q000523:psychology; D053206:Nocturnal Enuresis / Q000150:complications* / Q000453:epidemiology / Q000523:psychology; D015203:Reproducibility of Results; D012893:Sleep Wake Disorders / Q000453:epidemiology / Q000209:etiology* / Q000523:psychology; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires