Published on in Vol 5, No 2 (2021): February
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/21432, first published
.
![Usage and Weekly Attrition in a Smartphone-Based Health Behavior Intervention for Adolescents: Pilot Randomized Controlled Trial Usage and Weekly Attrition in a Smartphone-Based Health Behavior Intervention for Adolescents: Pilot Randomized Controlled Trial](https://asset.jmir.pub/assets/22c236e5a7511cb42d66d1e5478413fa.png 480w,https://asset.jmir.pub/assets/22c236e5a7511cb42d66d1e5478413fa.png 960w,https://asset.jmir.pub/assets/22c236e5a7511cb42d66d1e5478413fa.png 1920w,https://asset.jmir.pub/assets/22c236e5a7511cb42d66d1e5478413fa.png 2500w)
1 Department of Psychology, University of Iceland, Reykjavik, Iceland
2 Faculty of Medicine, University of Iceland, Reykjavik, Iceland
3 Children's Hospital, Landspitali University Hospital, Reykjavik, Iceland
*all authors contributed equally