Quality criteria and quality of the selected studies quality criteria.

1) Assignment intervention randomized; 2) Includer blinded for randomization order; 3) Employees blinded for treatment; 4) Practitioner blinded for treatment; 5) Assessor blinded for treatment (mental health outcomes); 6) Groups comparable at the start of the trial; 7) Follow up available of enough included employees at T1, etc. l; 8) Included employees analyzed in randomized group; 9) Same treatment of groups except the intervention.