Ketelaar 2013.

Methods	Cluster‐RCT, Netherlands
Participants	Nurses on wards of an academic hospital were screened for work and health problems: Experimental: 29 wards, 579 participants of which 139 screened positive Control: 29 wards, 561 participants of which 161 screened positive. Experimental 17% Control 22% men, > 45 years age Experimental 51% Control 46%, > 10 years of experience Experimental 51% Control 41%
Interventions	1) Experimental: Participants received personalised feedback on their screening results immediately after filling out the baseline questionnaire, both onscreen and in an e‐mail. The personalised feedback was followed by an invitation for a tailored offer of self‐help EMH interventions, on the basis of an algorithm based on the specific symptoms and the work‐relatedness of the symptoms. Participants were mostly offered a choice of 2 ‐ 3 EMH interventions to leave room for personal preferences. Participants who screened negative on all mental health complaints were invited to follow an EMH intervention aimed at enhancing and retaining their mental fitness. The EMH interventions are self‐help interventions on the Internet aimed at reducing specific mental health complaints or enhancing well‐being. The interventions are mainly based on the principles of cognitive behavioural therapy and combine a variety of aspects, e.g. providing information and advice, weekly assignments, the option of keeping a diary and a forum to get in contact with others who have similar complaints. The EMH interventions were developed as stand‐alone interventions by the Trimbos Institute (CBT) 2) Control: Waiting list: In the control arm. Participants filled out the baseline questionnaire; however, results of the screening questionnaires were not to be reported back to participants, and no further interventions were advised at baseline. As compensation, participants in the control arm received their personal screening results together with a tailored choice for a self‐help e‐mental health intervention six months after baseline.
Outcomes	The study used work‐functioning as the primary outcome: we used the distress part of the Dutch 4DKL as stress outcome; anxiety and depression were also measured but not reported
Notes	We got the following data from author S. Ketelaar: Distress measure with 4DKL at 6 months follow‐up for the group who screened positive: Experimental: N = 52 6.06 ± 6.54; Control: N = 116 6.82 ± 6.5.7
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	In order to guarantee allocation concealment, randomisation was performed by 1 researcher (KN) who was not involved in the practical recruitment of employees, using the computer software program Nquery Advisor with a block size of 3.
Allocation concealment (selection bias)	Unclear risk	see above
Blinding (performance bias and detection bias) All outcomes	High risk	Providers and participants not blinded; outcome self‐reported stress
Incomplete outcome data (attrition bias) All outcomes	High risk	Experimental: 80/178 = 44% lost to follow‐up; Control: 71/211 = 34% lost to follow‐up
Selective reporting (reporting bias)	High risk	Anxiety and Depression not reported
Other bias	High risk	Compliance with the intervention was extremely low