The Danish National Health Survey 2023: study design and participant characteristics

To describe the design of the Danish National Health Survey (DNHS) 2023, participants' demographic characteristics and differences in demographic and selected health-related characteristics between respondents invited by web-mode and paper-mode. A sample of 25,000 residents in Denmark aged 16 years or above was invited to participate in the DNHS 2023 using a mixed-mode approach (web/paper mode). Web-mode invited were additionally invited to participate in an accelerometer study. The self-administered questionnaire included 83 questions about health, health behaviour and morbidity. Descriptive statistics were used to describe characteristics associated with response and invitation mode. The response proportion was 40.8%. Non-response was more frequent among men, individuals of the youngest age groups, individuals with non-Western backgrounds, unmarried and individuals from densely populated areas. The response proportion was higher among web-mode invited (42.0%) than paper-mode invited (22.6%). Paper-mode invited respondents were more often women, aged 80 years or older, and widowed compared with web-mode invited respondents.