The Danish National Health Survey 2010. Study design and respondent characteristics.
OBJECTIVE
In 2010 the five Danish regions and the National Institute of Public Health at the University of Southern Denmark conducted a national representative health survey among the adult population in Denmark. This paper describes the study design and the sample and study population as well as the content of the questionnaire.


METHODS
The survey was based on five regional stratified random samples and one national random sample. The samples were mutually exclusive. A total of 298,550 individuals (16 years or older) were invited to participate. Information was collected using a mixed mode approach (paper and web questionnaires). A questionnaire with a minimum of 52 core questions was used in all six subsamples. Calibrated weights were computed in order to take account of the complex survey design and reduce non-response bias.


RESULTS
In all, 177,639 individuals completed the questionnaire (59.5%). The response rate varied from 52.3% in the Capital Region of Denmark sample to 65.5% in the North Denmark Region sample. The response rate was particularly low among young men, unmarried people and among individuals with a different ethnic background than Danish.


CONCLUSIONS
The survey was a result of extensive national cooperation across sectors, which makes it unique in its field of application, e.g. health surveillance, planning and prioritizing public health initiatives and research. However, the low response rate in some subgroups of the study population can pose problems in generalizing data, and efforts to increase the response rate will be important in the forthcoming surveys.
National Institute of Public Health, University of Southern Denmark, Øster Farimagsgade 5A, Copenhagen, Denmark. ach@niph.dk
Anne Illemann
AI
Christensen
Ola
O
Ekholm
Charlotte
C
Glümer
Anne Helms
AH
Andreasen
Michael Falk
MF
Hvidberg
Peter Lund
PL
Kristensen
Finn Breinholt
FB
Larsen
Britta
B
Ortiz
Knud
K
Juel
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D015340:Epidemiologic Research Design; D005260:Female; D006304:Health Status; D006306:Health Surveys / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011634:Public Health; D012107:Research Design; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult