Epton 2014.

Methods	Randomised controlled trial Location: Sheffield, UK Funding: The study was funded by the UK National Prevention Research Initiative (NPRI) Phase 4 (grant number: MR/J0004501/1) Recruitment: Participants were invited by email upon university registration. Participants were paid GBP 10 for completing all 3 questionnaires and were entered into a GBP 100 prize draw for each questionnaire they completed. The study was conducted from September 2012 to March 2013.
Participants	Participants (n = 1445) (Intervention n = 736; Control n = 709) were university students. Inclusion criteria were incoming undergraduate at the University of Sheffield. No overall participant baseline characteristics were reported. There were no differences between participants in the intervention and control arms in baseline measures of the 4 health behaviours. Gender and age did, however, differ between the 2 arms, with more women and younger participants in the intervention arm than in the control arm
Interventions	The intervention was a tailored and interactive Internet‐based intervention. Participants assigned to the intervention arm were directed to the U@Uni website and asked to complete a profile page that contained the self‐affirmation manipulation. After completing their profile, participants were asked to sign in to the website and view the online resources, which included theory‐based messages relevant to the targeted health behaviours and a planner that contained instructions to form implementation intentions. Participants were able to access information that was of interest to them. Participants could download a smartphone app which was available throughout the year Measurement‐only control
Outcomes	Outcome data were collected at 1 and 6 months. Outcomes were bioverified sustained cessation, portions of fruit and vegetables, physical activity alcohol consumption, health status, recreational drug use, BMI, Health Service usage, academic performance, social cognitive variable, and engagement with the digital intervention
Notes	The authors declare that they have no competing interests
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomly allocated using SurveyGizmo
Allocation concealment (selection bias)	Low risk	Participants were randomly allocated using SurveyGizmo
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rates: Intervention 40%, control 34%