Preventive Medicine 33, 313–324 (2001) doi:10.1006/pmed.2001.0889, available online at http://www.idealibrary.com on The Change-in-Stage and Updated Smoking Status Results from a Cluster-Randomized Trial of Smoking Prevention and Cessation Using the Transtheoretical Model among British Adolescents Paul Aveyard, M.P.H., 1 Emma Sherratt, Ph.D., Joanne Almond, M.Sc., Terry Lawrence, M.Sc., Robert Lancashire, B.A., Carl Griffin, M.Sc., and K. K. Cheng, Ph.D. Department of Public Health and Epidemiology, University of Birmingham, Birmingham B15 2TT, United Kingdom Published online August 23, 2001 The stages of change model underpins the British Gov- Background. The transtheoretical model (TTM) and ernment’s creation of a network of smoking cessation computer technology are promising technologies for clinics [1]. However, as it is often used, the stages of changing health behavior, but there is little evidence change model represents little more than a common- of their effectiveness among adolescents. sense approach that recognizes that some people are Method. Four thousand two hundred twenty-seven not yet ready to change their behavior, so detailed dis- Year 9 (ages 13–14) pupils in 26 schools were randomly cussion of the strategies of change with them is mis- allocated to control and 4,125 in 26 schools were allo- placed. In contrast, the transtheoretical model (TTM), cated to TTM intervention. TTM pupils received three from which the stages are derived, makes specific pre- whole class lessons and three sessions with an inter- dictions [2, 3]. Ten processes drive movement through active computer program. Control pupils received no the stages, according to the theory. Use of the correct special intervention. Positive change in stage and process in the correct stage will facilitate movement to smoking status was assessed from a questionnaire com- the next stage. Nonuse of the correct process or use of pleted at baseline, 1 year, and 2 years. Random effects other processes that are helpful in preceding or later logistic regression was used to compare the change in stages will hinder progress to the next stage. stage and smoking status between the arms. In 1999, we reported the results of a clinical trial of a Results. Eighty-nine percent of the TTM group and 89.3% of the control group were present at 1-year and computer program for adolescents [4]. The intervention 86.0 and 83.1%, respectively, were present at 2-year fol- consisted of three whole class lessons and three sessions low-up. The adjusted odds ratio (95% confidence inter- using a computer program during school year 9, when val) for positive stage movement in the TTM relative the adolescents were ages 13–14. The computer pro- to control was 1.13 (0.91–1.41) at 1 year and 1.25 (0.95– gram consisted of video clips of young people discussing 1.64) at 2 years and for regular smoking was 1.14 (0.93– their smoking, followed by questionnaires. The re- 1.39) at 1 year and 1.06 (0.86–1.31) at 2 years. Subgroup sponses to the questions were used to derive the young analysis by initial smoking status revealed no benefit person’s stage of change with respect to either acquisi- for prevention or cessation. tion of smoking or cessation. Further questions related Conclusions. The intervention was ineffective.  2001 to the other core concepts of the transtheoretical model: American Health Foundation and Academic Press decisional balance, temptations, and processes. After Key Words: randomized controlled trial; smoking pre- each questionnaire, young people using the program vention; smoking cessation; adolescence. were given feedback about how their process use com- pared with others in their stage and what to do to move INTRODUCTION to the next stage, for example. On the second and third occasions, students received feedback on progress since The stages of change model is the most used model the last occasion. The control group received standard of behavior change in British health promotion practice. lessons on smoking, which is part of the English na- tional curriculum. One year after the program began, 1 To whom reprint requests should be addressed. Fax: 0121 414 7878. E-mail: p.n.aveyard@bham.ac.uk. about 4 months after the last intervention in the TTM 313 0091-7435/01 $35.00 Copyright  2001 by American Health Foundation and Academic Press All rights of reproduction in any form reserved.