Sidani Souraya, Bootzin Richard R, Epstein Dana R, Miranda Joyal, Cousins Jennifer
Daphne Cockwell School of Nursing, Ryerson University, Toronto, Ontario, Canada.
Department of Psychology, University of Arizona, Tucson, United States.
Can J Nurs Res. 2015 Mar;47(1):17-34. doi: 10.1177/084456211504700103.
Preferences for treatment contribute to attrition. Providing participants with their preferred treatment, as done in a partially randomized clinical or preference trial (PRCT), is a means to mitigate the influence of treatment preferences on attrition. This study examined attrition in an RCT and a PRCT. Persons with insomnia were randomly assigned (n = 150) or allocated (n = 198) to the preferred treatment. The number of dropouts at different time points in the study arms was documented and the influence of participant characteristics and treatment-related factors on attrition was examined. The overall attrition rate was higher in the RCT arm (46%) than in the PRCT arm (33%). In both arms, differences in sociodemographic and clinical characteristics were found between dropouts and completers. The type of treatment significantly predicted attrition (all p ≤ .05). The results provide some evidence of a lower attrition rate in the PRCT arm, supporting the benefit of accounting for preferences as a method of treatment allocation.