Recruitment, randomization, and blinding
BLIND
Potential participants were identified by NAV and contacted through their secure electronic communication website. They received information about the project and accepted or declined participation through the same website. They were informed that whether they chose to participate or not, it would not affect their medical benefits in any way. A NAV employee, who also was a member of the project, verified eligibility for individuals who accepted to participate in the study and sent lists of participants to the researchers for randomization.Eligible individuals who signed consent were randomized to one of the three groups: MI, active control, or usual case management. To make sure the randomization was concealed for the researchers and participants, block randomization with unknown sizes was carried out using a web-based program provided by a third party, specifically the Unit of Applied Clinical Research at the Norwegian University of Science and Technology (NTNU). The researchers were blinded for group affiliation until all main analyses were performed and interpreted. It was not possible to blind participants or the NAV caseworkers offering the intervention.