A Comparison of Saliva Testing to Urinalysis in an Arrestee Population

Abstract

Past studies have concluded that individuals under criminal justice supervision often underreport their recent use of illicit drugs. To address this underreporting, objective biological measures, such as urine, saliva, and hair testing, have been used to gain better estimates of illegal drug use. While urinalysis is generally recognized as the reference standard, a method recently introduced in nonlaboratory settings for ascertaining drug use—saliva testing—may offer an alternative to urinalysis. To date, however, no studies have compared saliva testing to urinalysis among criminal justice populations. In the current study, urine and saliva specimens were collected from 114 adult arrestees interviewed as part of Maryland's Substance Abuse Need for Treatment among Arrestees (SANTA) project. With urinalysis as the reference standard, analysis of the saliva test results indicated sensitivity of 100% and specificity of 99% for cocaine and sensitivity of 88% and specificity of 100% for heroin. For marijuana, however, the saliva results indicated a sensitivity of only 5%. Anecdotal reports from the field suggest that saliva may have some advantages over urine because of the ease of collection, invulnerability to adulteration, and minimal personal invasiveness. These findings suggest that a more comprehensive study to evaluate the efficacy of saliva testing in field research may be warranted.