Blow 2006.

Methods	Parallel group RCT: brief intervention and tailored booklet versus brief intervention and generic booklet versus tailored booklet only (active control) versus generic booklet only (active control). ITT: yes.
Participants	Setting: USA; emergency department level 1 trauma centre. Participants: Aged ≥ 19 years and injured, displaying at risk or heavy episodic drinking. At risk drinking was defined as: ≥ 15 drinks per week for men aged < 65 years; ≥ 12 drinks per week for women aged < 65 years and men aged ≥ 65 years; and ≥ 9 drinks per week for women aged ≥ 65 years in the previous 3 months. Heavy episodic drinking was defined as ≥ 5 drinks/occasion on > 4 occasions in the last month (i.e. weekly episodes) for men < 65 years; ≥ 4 drinks per occasion on > 4 occasions in the last month for men ≥ 65 years and all women. Excluded if: severely injured (e.g. unconscious); in need of immediate life‐saving procedures; blood alcohol level > 200 mg/dL; self‐inflicted injury, sexual assault, overdose, poisoning, near‐drowning, chronic injury without specific event associated with re‐injury; pregnant; prisoner; or non‐English speaking. Screened with computerised health survey incorporating AUDIT‐C and DrInC; participants also received an alcohol salivary test before intervention, which proceeded once blood alcohol concentration reached 100 mg/dL or less. Number randomised = 575 (but following data are for 494 participants who were followed‐up); 71% male; mean age 27.8 years; 86% White, 6% Black, 8% other race; 80% some college education or higher. At baseline: mean number of drinks per week = 21.
Interventions	Participants were screened with a health survey incorporating AUDIT‐C and DrInC which served as baseline assessment (duration was not reported). Tailored manual/brief advice group (N = 129) received brief intervention before leaving the emergency department from a research social worker, during which the tailored booklet was reviewed with the participant. The tailored booklet was generated according to responses to the computerised screening tool. Tailored manual/no brief advice group (N = 121) received a tailored booklet from the research social worker who told them that, based on their responses to the health screen, they scored as at‐risk for hazardous drinking and should review the booklet. Generic manual/brief advice group (N = 124) received brief intervention before they left the emergency department from a research social worker, during which the generic booklet was reviewed with the participant. The generic booklet was identical to the tailored booklet in length, content and graphics but included standard rather that tailored text/graphics. Generic manual/no brief advice group (N = 120) received the generic booklet from the research social worker who told them that, based on their responses to the health screen, they scored as at‐risk for hazardous drinking and should review the booklet. Duration of intervention was not reported.
Outcomes	Mean number of drinks per week, number of binge drinking episodes (> 5 drinks for men, > 4 drinks for women) in previous month, DrInC score (alcohol‐related consequences). Assessed at 3 and 12 months.
Funding source	This study was supported by NIAAA grant AA111629.
Declaration of interests	Not reported.
Notes	Participants willing to complete the survey were entered into a monthly draw for USD 100. Participants were paid USD 20 for three month telephone follow‐up interview and USD 30 for 12 month telephone follow‐up. Loss to follow‐up: 81/575 (14%) (not reported according to study arms). Data (including baseline data) were reported only for participants who were followed up.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"A computer program automatically determined eligibility for the RCT and randomly assigned participants to one of four intervention conditions" (Blow 2006, p. 570). "To prevent the possibility that staff could unwittingly manipulate assignment to intervention condition, participants were randomly assigned to conditions via the computer using an urn randomisation technique" (Blow 2009, p. 487).
Allocation concealment (selection bias)	Unclear risk	Not reported.
Blinding of treatment providers	Low risk	Cluster randomised ‐ treatment providers only had contact with one arm and only delivered one intervention, reducing the chance of cross contamination.
Blinding of participants	High risk	No reported attempt to blind participants.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported.
Incomplete outcome data (attrition bias) All outcomes	High risk	Reported data only from those who completed not those randomised.
Selective reporting (reporting bias)	Low risk	Outcomes stated in methods were reported.