Fig. 1From: Spinal pain in Danish school children – how often and how long? The CHAMPS Study-DK a Participant flow CHAMPS 2 2011–2014. *Dropins: change of school or wish to enter the project. **Dropouts: change of school or personal reasons. b Participant flow SMS track. *Children participating less than maximum possible number of weeks minus one. **Children answering less than 50% of participation timeBack to article page