Christoff 2015.

Study characteristics
Methods	Study design: 3‐arm parallel‐group RCT   Duration of study: 3 months
Participants	Country: Brazil  Income classification: upper‐middle income between 2006 and 2015 Geographical scope: urban  Healthcare setting: university  Mental health condition: Alcohol Use Disorder  Population (mention whether patient, carer, or dyad)  1. Age: 18 years and older  2. Gender: both  3. Socioeconomic background: 58% of participants were in socioeconomic class B   4. Inclusion criteria (including threshold cutoff score of measurement tool)  a. College students from 2 universities with alcohol or substance abuse b. ASSIST score 4 to 26 (moderate) and above (dependent) for substance use and/or 11 to 26 (moderate) and above (dependent) for alcohol use  c. Ability and consent to participate in 2 sessions that lasted from 5 minutes (control group) to 40 minutes (other 2 groups) with no compensation or payment for participation d. Declaration that they would not engage in other substance treatments/programmes before or during the study  5. Exclusion criteria  a. None
Interventions	Stated purpose: to evaluate the efficacy of a computer‐based intervention programme, called ASSIST/Motivational Brief Intervention (ASSIST/MBIc), for substance involvement compared with only feedback about ASSIST scores (control group) and feedback plus MBI in an interview (ASSIST/MBIi)  INTERVENTION 1 (n = 128) Name: computer‐based ASSIST/Motivational Brief Intervention (ASSIST/MBIc)  Delivered by: computer programme   Title/name of PW and number: none   1. Selection: none  2. Educational background: none   3. Training (contents, duration, by whom): none   4. Supervision: none  Intervention details: NA (will not analyse)  1. Duration/frequency: NA (will not analyse)  INTERVENTION 2 (n = 106) Name: feedback plus MBI in an interview (ASSIST/MBIi)  Delivered by: CP (community professional) Title/name of PW and number: interviewers ‐ 6   1. Selection: not specified  2. Educational background: not specified   3. Training: in ASSIST and motivational interviewing by principal investigator using the WHO manual   4. Supervision: none specified  Intervention details   1. Duration/frequency: a single‐session brief intervention following the ASSIST interview lasting 5 to 20 minutes. Contents: a personal face‐to‐face intervention that provides feedback on scores, gives advice about identifying potential problems, encourages behavioural change, allows participants to report substance‐related problems, lists the advantages and disadvantages of using the substance(s), lists skills to cope with risky behaviours related to the substance(s), and provides goals to change behaviours in the short, medium, and long term. ASSISTi on follow‐up at 3 months  CONTROL (n = 99) Randomly screened by ASSISTi or ASSISTc and received feedback about the score. Wait‐list – received MBIi after the study ended      CO‐INTERVENTIONS: none
Outcomes	Patients  1. ASSIST Total* (Men, Women)  2. ASSIST Alcohol (Men, Women)  3. ASSIST Marijuana (Men, Women)  4. ASSIST Other Drugs (Men, Women) 5. ASSIST Tobacco (Men, Women)#   Carers  Nil  Process/health workers Nil  Economic outcomes (and where these can be found, e.g. ref or table number) Nil  (asterisk for study's primary outcomes; star: outcomes that we have not reported in this review)  Time points: 3 months
Notes	Source of funding: institutional (Universidade Federal do Paraná) support only  Notes on validation of instruments (screening and outcomes): validated  Additional information (e.g. provided by authors, existence of a published study protocol): declaration of interests ‐ all study authors reported no conflicts of interest Prospective trial registration number: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Judgement comment: Yen rated "unclear" and stated "random sequence generation is not described, apart from mentioning that each student received a personal code at time of enrolment"; Antonio rated "low" without comment. Final decision by Yen ‐ "unclear"
Allocation concealment (selection bias)	Unclear risk	Judgement comment: Yen rated "unclear" and stated "allocation concealment is not described"; Antonio rated "low" without comment. Final decision by Yen "unclear"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Yen rated "high"; "subjects received the intervention and were thus not blinded to their intervention. Assessments were performed by an interviewer or were self‐assessed using computer software. Blinding was not performed" Antonio rated "unclear"; final decision by Yen ‐ "unclear" because although study design made it difficult to blind subjects to their intervention; this may have influenced the outcome as it is self‐assessed for some participants
Blinding of outcome assessment (detection bias) all outcomes	High risk	Assessments were performed by an interviewer or were self‐assessed using computer software. Blinding was not performed
Baseline outcome measurements similar	Low risk	Baseline total involvement, tobacco, alcohol, marijuana, and other drug ASSIST scores were statistically similar in all 3 groups
Baseline characteristics similar?	Low risk	Randomisation successfully balanced intervention assignments and ensured equal characteristics in the groups (no signiciant differences; chi² test)
Incomplete outcome data (attrition bias) Efficacy data	Unclear risk	Students: 458 students scored on ASSIST; 4 did not agree to participate in the RCT (1 in the ASSIST/MBIi group, 3 in the control group). Over the course of the trial, 121 students were lost (14%; i.e. not found after 3 attempts by phone or personal contact within 1 month after scheduled follow‐up) or dropped out (11%; i.e. when they personally or by phone/email gave up the study), for an overall response rate of 75%. Twenty‐three per cent of ASSIST/MBIc, 25% of ASSIST/MBIi, and 28% of control did not complete the 2 sessions, with no significant differences among groups Significant dropout rate (25%) in total ‐ this may have influenced results had these participants not dropped out
Protection against contamination	Low risk	Judgement comment: both reviewers rated "low"
Selective reporting (reporting bias)	Unclear risk	No published clinical trial protocol available; outcomes planned in methods section were reported in results section
Other bias	Low risk	No other sources of bias were found