Alcohol Screening Tests: AUDIT, CAGE, MAST, Scoring, and Limits

Alcohol screening tests use questions or biological measurements to identify recent drinking risk or alcohol concentration. A screen supports the next clinical question; it does not diagnose alcohol use disorder or choose a treatment setting by itself.

Each tool has a defined entity, time frame, input, score, and limit. Questionnaires measure reported behavior and consequences. Breath tests measure alcohol in exhaled air at one point in time.

The correct tool depends on the question being asked: recent drinking risk, lifetime alcohol-related problems, drug-inclusive screening, or current breath alcohol concentration.

What Does an Alcohol Screening Test Measure?

An alcohol screening test measures a defined alcohol-related signal. AUDIT measures consumption, dependence symptoms, and harm over the prior year. CAGE measures lifetime alcohol-related concerns through four questions. MAST measures lifetime alcohol-related problems through a longer weighted questionnaire. A breathalyzer measures alcohol concentration in breath.

Screening and diagnosis are different processes. A clinician combines a result with history, impairment, medical factors, withdrawal risk, and current diagnostic criteria before deciding whether alcohol use disorder is present.

How Do AUDIT, CAGE, MAST, and Breathalyzer Tests Differ?

AUDIT, CAGE, MAST, and breathalyzer tests answer different alcohol questions. Each tool has a distinct input, reference period, and output.

Tool	Input	Time frame	Primary output
AUDIT	10 scored questions	Past 12 months	Risk level for hazardous or harmful alcohol use
CAGE	4 yes-or-no questions	Lifetime	Signal for further alcohol assessment
MAST	Longer weighted questionnaire	Lifetime	Pattern of alcohol-related problems
Breathalyzer	Exhaled breath sample	Current sample	Estimated breath alcohol concentration

Which Alcohol Screening Test Fits the Question?

AUDIT fits a broad adult alcohol-risk screen because it covers consumption, dependence symptoms, and harm. Its ten questions, AUDIT-C comparison, scoring bands, and validation limits are instrument-specific.

CAGE fits a brief lifetime case-finding conversation because it asks four consequence-focused questions. Its four questions, CAGE-AID adaptation, scoring, and population limits are instrument-specific.

MAST fits a lifetime alcohol-problem history because it asks about social, legal, occupational, and health consequences. Its versions, weighted scoring, and interpretation cautions are instrument-specific.

A breathalyzer fits a current alcohol-concentration question because it measures alcohol in breath. A breath result cannot establish a person's drinking pattern, alcohol use disorder, or treatment need.

How Are Alcohol Screening Scores Interpreted?

Alcohol screening scores are interpreted according to the instrument and population that produced them. A score has meaning only within that tool's scoring key, reference period, cutoff, and validation setting.

AUDIT uses ten items scored from 0 to 4, while CAGE uses four binary responses and MAST uses version-specific weighted responses. These different scales cannot be merged into one universal alcohol-risk number.

What Can an Alcohol Screening Test Tell You?

No, an alcohol screening test cannot diagnose alcohol use disorder by itself. Diagnosis requires a clinical assessment of symptoms, duration, impairment, medical context, and alternative explanations under current diagnostic criteria.

A positive screen identifies a reason for follow-up. After screening, a clinical assessment reviews whether a substance use disorder is present and what level of care is appropriate.

What Happens After a Positive Alcohol Screen?

A positive alcohol screen leads to clarification, risk review, and a decision about follow-up. A clinician confirms the answers, asks about withdrawal and safety, reviews co-occurring health concerns, and decides whether brief intervention, diagnostic assessment, or urgent medical care is needed.

When assessment confirms alcohol use disorder and a need for structured care, alcohol addiction treatment may combine withdrawal planning, medication, behavioral therapy, recovery support, and continuing care according to clinical need.

Withdrawal symptoms such as confusion, seizures, severe tremor, or hallucinations require urgent medical attention. A questionnaire score should never delay emergency care.

What Are the Limits of Alcohol Screening Tests?

Alcohol screening tests have limits because self-report, cutoff selection, setting, and timing affect the result. A person may underreport use, a brief tool may miss risky drinking, and a current breath result may not represent earlier or later alcohol exposure.

Validation statistics describe a defined instrument and population; they are not universal accuracy guarantees. A screen also does not measure every medical, psychiatric, social, or environmental factor that affects treatment planning.

What Is the Difference Between an Alcohol Questionnaire and a Breathalyzer?

An alcohol questionnaire measures reported behavior, while a breathalyzer measures alcohol in an exhaled sample. The questionnaire addresses patterns and consequences over a defined period. The breathalyzer addresses concentration at collection and requires device, calibration, and sample-quality controls.

Using both results may add context, but neither result independently establishes impairment, diagnosis, or treatment placement. A breathalyzer measures current breath alcohol and has device-specific limitations.