Interviewer-administered TLFB vs. self-administered computerized (A-CASI) drug use frequency questions: a comparison in HIV-infected drug users

Measures of days used primary drug showed high agreement whether assessed by interviewer-administered TLFB or by questions self-administered via the A-CASI modality. Differences by gender, ethnicity and age suggest some caution in using the TLFB, although additional studies are needed. However, findings generally indicate that studies based on one assessment method or the other can be compared with reasonable confidence.