Derived trail making test indices in a sample of substance abusers: demographic effects.

Derived indices on the Trail Making Test (TMT), a test often used to screen for cognitive impairments, were examined in a sample of substance abusers in drug abuse treatment programs. A mixed race sample was drawn from electronic files of data from the Drug Abuse Treatment Outcome Study (DATOS). The DATOS was a naturalistic, prospective cohort study that collected data from 1991 through 1993 within 96 programs in 11 cities in the United States. Data were analyzed to determine the effects of demographic variables on derived indices created by adding, subtracting, multiplying, and dividing parts A and B of the TMT in this large treatment sample of substance abusers. The variables of sex, age, ethnicity, and education were statistically significant for selected derived indices of the TMT.