The aim of this study is to examine the potential for animation movies to improve response rates and sample composition in an embedded randomized controlled trial in the Danish National Health Survey 2021. The overall research question is whether cover letters including an animation movie can perform better than generic letters.

The aim of this study is to examine the potential of animation videos to improve response rates and sample composition in an embedded randomized controlled trial in the Danish National Health Survey 2021 (DNHS-2021). The overall research question is whether digital cover letters including an animation video can perform better than digital letters without animations. The proposition is that such letters should increase the willingness of some sample members to participate by means of increased motivation and reduced complexity, and that this will be reflected in higher response rates. In addition to examining whether it can be advantageous for overall response rates to use cover letters including animation videos, this study also examines the effect of different versions of the animation videos across sample subgroups in order to identify how to best target potential non-respondents in future surveys.

Inclusion Criteria:

• Aged 16 years or older and living in Denmark at January 1th 2021.
• Able to receive an invitation through a secure electronical mail service (Digital Post).