Illicit Drug Use, Acquiring Information On

Self-Reports

Among the advantages of self-reports are that they can provide estimates of illicit drug use over a very long time window (e.g., ‘Have you ever, in your life, used …’) that cannot be matched by biological measures, which provide only an assessment of a single recent point in time. Self-reports can also provide qualitative data on how a substance was consumed, motivation for use, and also circumstances of use, none of which can be obtained from biological measures.

Various approaches are used to collect quantifiable self-report data. Among the older methods are paper surveys that the respondent completes and interviews where the interviewer asks the questions and completes the questionnaire. Newer methods include the use of laptop computers, PDAs, and other electronic devices on which the respondent completes either the whole survey or confidential portions of it. Other methods include automated telephone interviews and, recently, Internet-based surveys.

Self-reports of illicit drug use are highly variable in terms of consistency (reliability) and accuracy (validity). Consistency and accuracy are affected by multiple factors, including memory, cognition, and psychological processes, the latter including tendencies toward deception (whether deliberate or unconscious) and social desirability. Memory failures lead to haphazard errors, such as guessing, or to systematic errors such as forward telescoping, where events are incorrectly remembered as having occurred more recently than the actual occurrence. Cognitive factors include the tendency for people to use enumeration or counting to recall infrequent events, while remembering frequently occurring events (e.g., ‘How many cigarettes do you smoke in a day?’) as rates, resulting in less accurate estimation as the means of providing a quantity. When the events are too numerous for each one to be recalled independently, rates are used. Thus, an individual who smokes 30 cigarettes in a day is unlikely to remember each of them. Instead such individuals remember how many per hour, or how often they need to buy a new pack of 20.

Deliberate deception is highly situation dependent and tends to result in underreporting of use. Lower accuracy rates occur in situations where there are negative consequences for use, such as in the criminal justice system, where individuals may potentially fear legal results of exposure. Perceived negative consequences are probably the most important variable implicated in deliberate deception. Self-deception occurs when individuals tell the inquirer what they perceive as the truth, but after having deceived themselves (e.g., ‘I don't need heroin. I could quit at any time. I just like it’ or ‘I don't need a drink before lunch; I just like it.’). Finally, social desirability is the inclination to respond to questions in a socially approved manner. This may result in either overor underreporting of use, depending on the context. For instance, youth in high school might exaggerate marijuana use to boost their standing with peers. Alternately, pregnant casual smokers may present themselves as nonsmokers due to the social opprobrium associated with any substance use during pregnancy. Some researchers have suggested that there is a personality component that influences the tendency to produce socially desirable responses.

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