The main study will be preceded by a pilot study (anticipated start medio august 2017). The aim of the pilot is to test the practical aspects of the study. If no changes are made to the study protocol, the intervention or one of the other arms, participants from the pilot will be included in the main study, In case of modifications to the study protocol after the pilot, participants from the pilot study will not be included in the main study. Data for primary and secondary outcomes will not be assessed before the end of the main study.