Cost effectiveness of screening for clinical trials by research assistantsversus senior investigators

This study evaluates the relationship between interviewer level of experien ce and the positive predictive value and cost of telephone screening of sub jects for randomized clinical trials. This is a previously uninvestigated a rea. Respondents to advertisements for chronic depression treatment researc h received brief, semi-structured telephone interviews (N=347) either by re search assistants (RAs) or by a senior investigator (SI). Those who met cri teria based on the phone interview were then interviewed in person using th e SCID-P. The RAs did not significantly differ from the SI in the proportion of phone screen positives who were also SCID positive or the proportion of phone sc reen positives who were randomized. While the SI performed phone interviews significantly faster than the RAs, the SI's higher salary generated a phon e screening cost per randomized subject 56% more than that of RAs. The resu lts suggest that trained research assistants are more cost effective than s enior investigators for initial screening of depressed patients for researc h protocols. Further studies are needed to determine whether the findings r eported would generalize to other research settings or patient populations. (C) 1999 Elsevier Science Ltd. All rights reserved.