Buckman 2015.

Study characteristics
Methods	Randomised controlled trial, parallel‐group assignment, open‐label study
Participants	72 healthy participants with average age of 21.7 years (SD = 0.9). Among participants, 44% were female Exclusion criteria: Younger than 21 years of age Reported consuming fewer than 4 drinks (3 drinks for women) twice per month in the past year, or Were more than 20% overweight or underweight from the ideal for gender, height, and body frame based on the Metropolitan Life Height–Weight Table Regular (greater than monthly) drug use Self‐report of current learning disability Lifetime history of bipolar disorder or psychosis diagnosis Substance use treatment in the past year Biological mother with heavy substance use during pregnancy For women, pregnancy
Interventions	95% ethanol with mixer (orange, cranberry, and lime juice) calculated based on body weight: 0.90 mL/kg for men, 0.78 mL/kg for women Physiologically inactive dose of alcohol (100 µL EtOH float per each cup) with mixer Placebo (100% mixer, no alcohol) Each beverage was divided into 3 equal drinks, and participants were instructed to consume each beverage evenly over a 5‐minute period (total drinking time = 15 minutes)
Outcomes	Variability in cardiovascular function: heart rate variability (HRV), high‐frequency HRV, low‐frequency HRV, stroke volume variability (mL), pulse transit variability (ms), systolic blood pressure variability (mmHg) Average cardiovascular activity: heart rate (bpm), stroke volume (mL), pulse transit time (ms), systolic blood pressure (mmHg), mean arterial blood pressure (mmHg) Sensitivities of cardiovascular function: heart rate baroreflex sensitivity, stroke volume baroreflex sensitivity, vascular tone baroreflex sensitivity
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	“Participants were randomly assigned to the alcohol, placebo, or no‐alcohol beverage group” "Upon arrival in the laboratory, weight, height, pregnancy status, and a zero blood alcohol concentration (BAC) were confirmed and participants were randomly assigned to the alcohol, placebo, or no‐alcohol beverage group, as described below" "Table 1 shows that groups were not statistically different in terms of demographics, family history of alcohol dependence, alcohol use, and mood" Comment ‐ adequate randomisation was probably done and baseline characteristics between groups were well matched
Allocation concealment (selection bias)	Unclear risk	Comment ‐ method of allocation concealment was not described
Blinding of participants and personnel (performance bias) All outcomes	High risk	“Participants in the alcohol group (n = 24) were told that they would receive some amount of alcohol and were given mixer (orange, cranberry, and lime juice) with an active ethanol…” “Participants in the placebo group (n = 24) were told that they would be given some amount of alcohol and received mixer with a physiologically inactive dose of alcohol…” “The no‐alcohol control group (n = 24) were told that they would not be given alcohol and received 100% mixer” Comment ‐ study was not blinded for participants and personnel
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment ‐ study was not blinded for outcome assessors
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment ‐ all participants were included in the final analysis (additional information from study author)
Selective reporting (reporting bias) For systolic blood pressure (SBP)	Low risk	Comment ‐ study authors reported SBP and SD
Selective reporting (reporting bias) For diastolic blood pressure (DBP)	High risk	Comment ‐ study authors did not report DBP
Selective reporting (reporting bias) For mean arterial blood pressure (MAP)	Low risk	Comment ‐ study authors reported MAP and SD
Selective reporting (reporting bias) For heart rate (HR)	Low risk	Comment ‐ study authors reported HR and SD
Other bias (conflict of interest, industry sponsorship)	Low risk	"This study was funded with the support of K01AA017473, K02AA00325, K24AA021778, R21AA020367, and HHSN275201000003C"
Other bias (was the study registered in clinical trials.gov/ was the protocol available?)	High risk	Comment ‐ protocol was not registered and study identifier was not reported