Table 1.

Comparison of Ingestion and Infusion Paradigms

Aspect of Method	Ingestion	Intravenous Infusion
Control: controlled variable for alcohol administration	Dose of alcohol ingested	BrAC Trajectory
Control: main barrier to precision	Uncontrollable absorption	BrAC meter precision
Control: individual peak BrAC	SD ~ 20-30% of intended mean	SD ~ 3% of intended mean
Control: latency to peak BrAC	SD ~ 25 min	SD ~ 2 min
Control of overall BrAC trajectory	Poor: see Figure 1A-1C	Precise: see Figure 1D
Control: first pass metabolism	Uncertain and uncontrollable	None
Power: Influence on size of sample population required for adequate hypothesis testing	Determined by concern for dealing with within-group variability in brain exposure to alcohol during analysis	Maximized by elimination of absorption and individualized modeling of alcohol distribution and elimination kinetics
Safety: reservoir effect	Unavoidable	Does not exist
Safety: peak BrAC	Mean value limited by uncertainty: absorption kinetics vs. toxicity	Limited by toxicity only: investigator specifies a preset value that cannot be exceeded by participants.
Ability to control beverage characteristics, including concentration, amount, taste, aroma, texture, and temperature	Excellent, but need to control them all, and to know relationship of each to subject’s preference	No beverage, but important to know infusate alcohol concentration, and to control infusate temperature
Ability to blind the first data-collection technician regarding alcohol vs. control beverage	Good	Currently unavailable
Ability to control for expectancy effects with an effective placebo control	Good to excellent depending on aspects of study design	Good to excellent depending on aspects of study design
Use of preferred alcoholic beverages	Feasible but uncommon	Not applicable
Presence of sensory cues associated with alcohol consumption	Excellent; olfactory and taste cues and behavioral responses (e.g., drinking from a glass).	Limited on purpose, but can be added depending on experimental question
Documentation of BrAC achieved	Stored, BrAC meter readings; unchecked if technician blinded	Real-time, monitored BrAC meter readings and continuous estimate of BrAC
Documentation of events, comments	Manual, changeable record	Time-stamped, permanent record
Documentation of dosing schedule in each session	Intermittent, by technician	Continuous, by CAIS
Laboratory settings where research can be conducted	Includes simulated bar, lab, simulated living room, fMRI, CT, etc.	Includes simulated bar, lab, CT, SPECT, PET, and fMRI
Inclusion of social interaction as variable of interest	Possible, limited, published	currently limited, unpublished
Repeated within-session administrations	Easy, but unreliable result	Easy and reliable
Ability to study acute within-session tolerance	Possible but typically confounded by limb effects	Easy and reliable
Main domain of validity	Ecological route of administration	Ecological alcohol exposures
Cost; # technicians required for per-session data collection	Minimum of 1; 2 if blinding required	Minimum of 1; 2 if blinding required
Cost: preparation of beverage/alcohol administered	Variable; usually by lab technician from readily available components	Infusate: $150 – $300 per session; usually performed by a research pharmacy
Cost: optimization of alcohol delivery paradigm	Variable depending on investigator experience	20 hours including free consultation using CAIS simulation mode
Cost: training of technicians	Weeks on protocol	Weeks on protocol + Days on CAIS
Cost: CAIS hardware	$0	$2,500 - $4,000
Cost: CAIS software	$0	$0 if paradigm used anywhere previously
Cost: CAIS bench testing	$0	Free, but shipping at cost
Cost: CAIS training	$0	~ $500 a day + travel

Note. BrAC= Breath Alcohol Concentration; CAIS= Computer Assisted Infusion Software