Preference in random assignment: implications for the interpretation of randomized trials

UMMS Affiliation

Department of Psychiatry

Publication Date


Document Type



*Consumer Satisfaction; Health Services Research; Humans; Patient Dropouts; *Random Allocation; *Randomized Controlled Trials as Topic


Health Services Research | Mental and Social Health | Psychiatric and Mental Health | Psychiatry | Psychiatry and Psychology


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.

Rights and Permissions

Citation: Adm Policy Ment Health. 2009 Sep;36(5):331-42. Epub 2009 May 12. Link to article on publisher's site

Journal/Book/Conference Title

Administration and policy in mental health

Related Resources

Link to Article in PubMed

PubMed ID