Screening for Illicit Drug Use-Adult

Screening for Illicit Drug Use-Adult

Screening for Illicit Drug Use

Summary of Recommendation and Evidence

Population Recommendation Grade
(What's This?)
Adolescents, Adults, and Pregnant Women

The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of primary care--based behavioral counseling interventions to prevent illicit drug use, including nonmedical use of prescription drugs, in children, adolescents, and young adults.

See the Practice Considerations section for suggestions for practice regarding the I statement.

 I

Go to Table 1 for a description of the USPSTF grades and Table 2 for a description of the USPSTF classification of levels of certainty regarding net benefit.

Importance: Illicit drug use and abuse are serious problems among adolescents, adults, and pregnant women in the United States, ranking among the 10 leading preventable risk factors for years of healthy life lost to death and disability in developed countries. (Please note that tobacco use and alcohol misuse are considered in separate screening recommendations of the USPSTF.)

Detection: While standardized questionnaires to screen adolescents and adults for drug use/misuse have been shown to be valid and reliable, there is insufficient evidence to assess the clinical utility of these instruments when applied widely in primary care settings.

Benefits of detection and early treatment: There is good evidence that various treatments are effective in reducing illicit drug use in the short term. Evidence is insufficient, however, either to demonstrate that treatment reliably improves social and legal outcomes for patients, or to link treatment directly to longer term improvements in morbidity or mortality. Since all but one published clinical trial of treatment interventions involved individuals who had already developed problems due to their drug use, it is not known whether the findings are generalizable to asymptomatic individuals whose illicit drug use is detected through screening. There is fair evidence that, regardless of the patient's history of treatment, reducing or stopping drug use is associated with improvement in some health outcomes. 

Harms of detection and early treatment: There is little evidence of harms associated with either screening for illicit drug use or behavioral interventions used in treatment. Several clinical trials of pharmacotherapy for drug misuse have reported mild to serious adverse events, although some of these events were likely related to underlying drug use. The specific adverse events noted to occur more frequently in the treatment arm of trials (compared to placebo) have been previously recognized as potential side effects of the treatment medication and cited on its product label.

USPSTF assessment: The USPSTF concludes that for adolescents, adults, and pregnant women, the evidence is insufficient to determine the benefits and harms of screening for illicit drug use. 

Patient Population under Consideration

This recommendation applies to children (11 years and younger), adolescents (aged 12-17 years), and young adults (aged 18-25 years), including pregnant persons. The purpose of this recommendation is to assess the evidence on interventions to prevent the initiation of illicit drug use and thus does not apply to persons who already have a history of regular or harmful illicit drug use. Children, adolescents, and young persons who are regular users of illicit drugs (at least once per week) or have been diagnosed with a substance use disorder are outside the scope of this recommendation.

Screening for illicit drug use in adults and adolescents (aged 12-17 years) is covered in a separate recommendation statement

Patterns of Drug Use

Marijuana is the most commonly used illicit drug in the United States, with about 6% of the population age 12 and older admitting to use within the past month. While cocaine is the second most commonly used illicit drug, it is used by less than 1% of the population. Only a small minority of Americans use hallucinogens, inhalants, heroin, or illicitly manufactured methamphetamine, although the potential for abuse of or dependence on these substances is high. Illicit (non-medical) use of prescription-type drugs, categorized as pain relievers, tranquilizers, stimulants, and sedatives, is a growing health problem in the U.S.

Screening Tests

While clinicians should be alert to the signs and symptoms of illicit drug use in patients, the added benefit of screening asymptomatic patients in primary care practice remains unclear. Toxicologic tests of blood or urine can provide objective evidence of drug use, but such tests do not distinguish between occasional users and those who are impaired by drug use. A few brief, standardized questionnaires have been shown to be valid and reliable in screening adolescent and adult patients for drug use/misuse. However, the clinical utility of these questionnaires is uncertain. The reported positive predictive values are variable and at best 83% when the questionnaires are applied in a general medical clinic. Moreover, the feasibility of routinely incorporating the questionnaires into busy primary care practices has yet to be assessed. The validity, reliability, and clinical utility of standardized questionnaires in screening for illicit drug use during pregnancy have not been adequately evaluated.

Treatment

Although drug-specific pharmacotherapy (e.g., buprenorphine for opiate abuse) and/or behavioral interventions (e.g., brief motivational counseling for cannabis misuse) have been proven effective in reducing illicit drug use in the short term,  the longer-term effects of treatment on morbidity and mortality have been inadequately evaluated.  Moreover, these treatments have been studied almost exclusively in individuals who have already developed medical, social, or legal problems due to drug use, and their effectiveness in individuals identified through screening remains unclear. In all but one trial, treatment was delivered outside the primary care setting, often in specialized treatment facilities. More evidence is needed on the effectiveness of office-based treatments for illicit drug use/dependence.

Other Approaches to Prevention

While interventions to prevent or reduce illicit drug use have been proposed for use in schools and sites of employment, evidence assessing preventive measures delivered in settings other than primary care practice was outside the scope of the USPSTF review. However, the Centers for Disease Control and Prevention's (CDC) Task Force on Community Preventive Services has announced plans to assess the effectiveness of selected population-based interventions for preventing or reducing abuse of drugs (other than tobacco and alcohol) and to make recommendations based on these findings.