To determine if urine drug tests
(UDTs) can detect under-reporting of drug use (ie, negative self-report, but positive UDT) and identify patient characteristics associated with underreporting when treating substance use disorders in primary care
Self-reported use (last 30 d) and UDTs were gathered at baseline, 3, 6, 9, and 12 months from 829 primary care
patients participating in a drug use intervention study. Rates of under-reporting were calculated for all drugs, cannabis, stimulants, opioids, and sedatives. Logistic regressions were used to identify characteristics associated with under-reporting.
Among the participants, 40% (n = 331) denied drug use in the prior 30 days despite a corresponding positive UDT during at least 1 assessment. Levels of under-reporting during 1 or more assessments were 3% (n = 22) for cannabis, 20% (n = 167) for stimulants, 27% (n = 226) for opioids, and 13% (n = 106) for sedatives. Older (odds ratio [OR] 1.04), female (OR 1.66), or disabled (OR 1.42) individuals were more likely to under-report any drug use. Under-reporting of stimulant use was also more likely in individuals with lower levels of educational attainment, previous arrests, and family and social problems. Under-reporting of opioid use was more likely in those with other drug problems, but less likely in those with better physical health, more severe alcohol and psychiatric comorbidities, and African-Americans.
With the exception of cannabis, UDTs are important assessment tools when treating drug use disorders in primary care
. UDTs might be particularly helpful when treating patients who are older, female, disabled, have legal and social problems, and have more severe drug problems.