Addiction Medicine: Closing the Gap between Science and Practice

possible, the extent to which they have clinical

utility for screening versus assessment purposes.

General Substance Use Screening

and Assessment Tools*

Alcohol, Smoking and Substance

Involvement Screening Test (ASSIST)

Developed by the World Health Organization

(WHO) in 1997, the Alcohol, Smoking and

Substance Involvement Screening Test is an

interviewer-administered screening tool for

primary care settings.^12 The eight-question

instrument measures the frequency of current

and lifetime use of tobacco, alcohol and illicit

drugs and the problems adult respondents have

experienced due to their use.^13 Each question is

structured to identify tobacco, alcohol, cannabis,

cocaine, amphetamine-type stimulant, inhalant,

sedative, hallucinogen, opioid and other drug

use and related problems resulting from use.^14

Each question has a set of responses with

corresponding numerical scores. For tobacco

and illicit drugs, the WHO recommends that

patients with specific substance involvement

scores of three or lower receive no intervention

aside from information about the substances

they use; those with scores between four and 26

receive a brief intervention; and those with

scores of 27 or higher receive an intensive

intervention or treatment. For alcohol, this

breakdown is 10 or lower, 11 to 26 and 27 or

higher, respectively.† 15

The ASSIST requires training to administer

properly.^16 The WHO recommends practitioners

understand why screening is important; how to

implement, administer and score the screening

instrument; and how to conduct follow-up

activities to help patients at different levels of

risk. Trainings also should include role-play and

supervised practice.^17

Although it is copyrighted, the instrument along

with the scoring manual are available free of

charge through the WHO.^18

* Select substance-specific screening tools are

presented later in the appendix.

† The total substance involvement score is calculated

by adding scores based on a patient’s responses to all

eight questions across all 10 substance categories.

Determining the Clinical Utility of a

Screening or Assessment Instrument

The psychometric properties of instruments

typically are established prior to their use in

research or clinical settings. The main

properties examined are validity and

reliability.^4

There are three primary measures of validity:

construct, content and criterion validity.^5

Construct validity determines the degree to

which the instrument is related to the

theoretical concept being measured;^6 content

validity is the extent to which items included in

the instrument represent the area of interest that

the instrument is designed to measure;^7 and

criterion validity determines whether the

instrument is related to external criteria,^8 such

as diagnostic criteria for a disease.

Reliability determines whether the instrument

produces consistent results that can be

reproduced.^9 Test-retest reliability refers to the

stability of the instrument in terms of the

consistency of a respondent’s score when

tested multiple times;^10 inter-rater reliability

determines whether the instrument produces

stable results across different observers; and

internal reliability (or consistency) determines

whether the items in a multi-item instrument

correlate with one another.^11

Two other important properties of an

instrument are its sensitivity--its ability to

identify accurately those with a particular

characteristic, in this case a certain level of

substance involvement, as having the

characteristic, and specificity--its ability to

identify accurately those without a particular

characteristic as not having the characteristic.

Although the statistics associated with these

properties are beyond the scope of this report,

these properties are discussed in a general way,

where available and relevant, to help give a

sense of the clinical utility of a particular

instrument.