People with an alcohol addiction problem consume an average of 26.3 (sd = 12.4) drinks per week (Cournoyer et al., 2010). To observe a decrease of 25% in this average number of drinks for the group participating in the program  My Choices  immediately compared to the delayed group at 3 months, we need a sample size of 100 participants. This calculation assumes an alpha of 5%, a power of 80% and unbalanced groups due to the randomization method used. Considering an attrition rate of 11.3% at 3 months and 20% at 6 months (Tremblay et al., Submitted), it will be necessary to recruit at least 120 participants to maintain the required number for analyses.~References Cournoyer, L.-G., Simoneau, H., Landry, M., Tremblay, J., & Patenaude, C. (2010). Évaluation d'implantation du programme Alcochoix+ (FQRSC #2008-TO-120890). F. q. d. r. s. l. s. e. l. culture.~Tremblay, J., Dufour, M., Bertrand, K., Saint-Jacques, M., Ferland, F., Blanchette-Martin, N., Savard, A.-C., Côté, M., Berbiche, D., & Beaulieu, M. (Submitted). Efficacy of a Randomized Controlled Trial of Integrative Couple Treatment for Pathological Gambling (ICT-PG): 10-Month Follow-Up. Journal of Consulting and Clinical Psychology.
The aim of the study is to assess the efficacy of the My Choices - Alcohol program by comparing alcohol-use of people before and after doing the program to people that did not do the program on the same period of time (3 months).