Preference in random assignment: implications for the interpretation of randomized trials.
Random assignment to a preferred experimental condition can increase service engagement and enhance outcomes, while assignment to a less-preferred condition can discourage service receipt and limit outcome attainment. We examined randomized trials for one prominent psychiatric rehabilitation intervention, supported employment, to gauge how often assignment preference might have complicated the interpretation of findings. Condition descriptions, and greater early attrition from services-as-usual comparison conditions, suggest that many study enrollees favored assignment to new rapid-job-placement supported employment, but no study took this possibility into account. Reviews of trials in other service fields are needed to determine whether this design problem is widespread.
Community Intervention Research, McLean Hospital, Belmont, MA 02478, USA. cmacias@mclean.harvard.edu
Cathaleene
C
Macias
Paul B
PB
Gold
William A
WA
Hargreaves
Elliot
E
Aronson
Leonard
L
Bickman
Paul J
PJ
Barreira
Danson R
DR
Jones
Charles F
CF
Rodican
William H
WH
Fisher
D003258:Consumer Behavior; D006302:Health Services Research / Q000458:organization & administration*; D006801:Humans; D010352:Patient Dropouts; D011897:Random Allocation; D016032:Randomized Controlled Trials as Topic