Pretreatment Attrition in a Comparative Treatment Outcome Study on Panic Disorder.
Hofmann, Stefan G. PhD; Barlow, David H. PhD; Papp, Laszlo A. MD; Detweiler, Michael F. BA; Ray, Susan E. MS; Shear, M. Katherine MD; Woods, Scott W. MD; Gorman, Jack M. MD
[Article] American Journal of Psychiatry. 155(1):43-47, January 1998.

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Objective: Whereas the fact of attrition during the course of treatment is well documented, little is known about the factors that affect sample selection before the beginning of a study ("pretreatment attrition"). The present study reports on the degree and sources of pretreatment attrition at two sites of a multicenter study on panic disorder that compared treatment outcomes for imipramine and cognitive behavior therapy.

Method: Data were collected at two clinical research sites, one with a pharmacological treatment orientation (N=420) and one with a psychosocial treatment orientation (N=208).

Results: The main source of pretreatment attrition was participant refusal. At both research sites, eligible patients most often refused participation because they were either unwilling to start treatment with imipramine (30.6% and 47.4%, respectively) or discontinue their current medication (22.6% and 35.1%, respectively).

Conclusions: Results from comparative treatment outcome studies are limited not only to people who meet the study criteria but also to those who are willing to begin a medication treatment and discontinue their current medication.

(Am J Psychiatry 1998; 155:43-47)

Copyright (C) 1998 American Psychiatric Association.