Derived trail making test indices in a sample of narcotic/other opiate abusers: demographic effects.

Derived indices on the Trail Making Test (TMT), a test often used to screen for cognitive impairment, were examined in a sample of 191 narcotic/other opiate 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 1991-1993 in 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 age, ethnicity, and education were statistically significant for the total score (A + B) and interaction score (A x B/100) derived indices of the TMT. In addition, the difference score (B - A) was statistically significant for education. The ratio score (B/A) was not significant for any demographic variable.