Is contemplation a separate stage of change to precontemplation?
BACKGROUND
Fundamental to a stage-based model of health behavior change is the assumption that there is non-linearity (or discontinuity) in the relationship between predictors and outcomes across stage boundaries. There is, however, little evidence to suggest the stages of the transtheoretical model (TTM) meet this assumption.


OBJECTIVE
The aim of this study was to extend previous work on discontinuity in prediction to the TTM stage boundary between precontemplation and contemplation, and to test the homogeneity of the contemplation stage of change.


METHODS
Repeated measures design with telephone surveys conducted two weeks apart. Participants were 708 randomly selected smokers, aged 18-40 years, in the precontemplation and contemplation stages of change.


RESULTS
An initial test of the stage boundary between precontemplation and contemplation revealed greater predictive power of a multivariate model in the precontemplation stage. Some evidence of discontinuity in prediction was found within the contemplation stage, between those "open to the possibility" of quitting and those "actually thinking about it." The discontinuity at the TTM boundary was reduced following the exclusion of precontemplators not interested in quitting and when those thinking about quitting within contemplation were also excluded.


CONCLUSIONS
The stage boundary between precontemplation and contemplation was not strongly supported, and there was weak evidence of a discontinuity within contemplation. The findings question the utility of the current operationalization of the TTM stage boundary.
VicHealth Centre for Tobacco Control, The Cancer Council Victoria, Carlton, Victoria, Australia. james.balmford@cancervic.org.au
James
J
Balmford
Ron
R
Borland
Sue
S
Burney
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D033182:Intention; D007407:Interviews as Topic; D008137:Longitudinal Studies; D008297:Male; D008960:Models, Psychological; D009042:Motivation; D016540:Smoking Cessation / Q000523:psychology*; D014029:Tobacco Use Disorder / Q000523:psychology / Q000534:rehabilitation