The Danish health and morbidity surveys: study design and participant characteristics.

Data from the Danish Health and Morbidity Surveys reveal an increasing proportion of the respondents to complete web questionnaires instead of paper questionnaires. Even though the response rate remained relatively stable in 2017, declining response rates is a major concern in health surveys. As the generalizability to the Danish population may be compromised by a low response rate, efforts to increase the response rate or keep it stable are crucial in future surveys. Thus, efforts should be made to ensure convenience and feasibility in relation to access to and the completion of survey (web) questionnaires.