Pardavila‐Belio 2015.

Methods	Country: Spain Recruitment was over 2 campuses and 14 college schools. Methods used to recruit participants included announcements on university signboards, newspapers, website and emails inviting all undergraduate and masters students to participate
Participants	255 college student smokers (intervention = 133, control = 122) (age 18 ‐ 24 years, mean = 20.1 years intervention, 20.5 years control) 38% were men
Interventions	1. Intervention arm received a 50‐minute motivational interview conducted by a nurse with online self‐help material. The follow‐up included a reinforcing email and group therapy 2. The control group received brief advice (5 ‐ 10 minutes) and a self‐help pamphlet, Stop Smoking
Outcomes	Self‐reported abstinence, with biochemical verification at 6 months (urine cotinine measurement)
Notes	New for 2017 update 37.6% of the participants randomised to the intervention group did not receive the complete protocol Funding: funded by the María Egea Foundation, University of Navarra (Spain) Declarations of interest: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated allocation method. 1 member of the team generated a blocked random number sequence, using Epilnfo version 7.0.9.7, and prepared sealed opaque sequentially‐numbered enveloped (1 ‐ 255) with the corresponding condition written inside. After each student agreed to participate in the study, the envelope was opened, determining the group to which he or she would be assigned
Allocation concealment (selection bias)	Low risk	Nurse and student unaware of which arm participant would be assigned to until envelope opened
Incomplete outcome data (attrition bias) All outcomes	Low risk	11/122 control and 19/133 intervention lost to follow‐up