Palmtop-assisted self-interviewing for the collection of sensitive behavioral data: randomized trial with drug use urine testing.

Palmtop-assisted self-interviewing (PASI) may provide a cheaper and more mobile alternative to audio-computer-assisted self-interviewing (ACASI) for collecting sensitive behavioral data. To evaluate PASI, in late 2002 the authors enrolled 1,283 Thai students aged 15-21 years in a randomized trial. Data collection used PASI, ACASI, self-administered questionnaire, and face-to-face interview in combination with drug-use urine testing. By use of reported levels of behaviors and agreement between self-reports of smoking and urine test results, PASI and ACASI (alpha = 0.05) were compared for noninferiority, and PASI and interview were compared for superiority (alpha = 0.05). Noninferiority of PASI was demonstrated by use of self-reports of the most sensitive areas of sexual behavior (e.g., oral sex, sexual intercourse, commercial sex, history of genital ulcers, pregnancy), as well as self-reports of less sensitive behaviors (e.g., alcohol use, dietary behaviors, symptoms of depression). Data generally showed noninferiority of PASI, ACASI, and self-administered questionnaires when compared with each other and superiority of PASI, ACASI, and self-administered questionnaires when compared with interviews. PASI agreements between self-reports of tobacco smoking and presence of nicotine metabolites in urine were noninferior to ACASI and superior to interviews. The establishment of PASI noninferiority and superiority using behavioral and biologic measures suggests that PASI is a scientifically acceptable alternative for collecting sensitive behavioral data.