| The Transtheoretical Stages of Change Model (TTM) has been applied to health promotion programs as one of the most prominent models of behavior change. This study investigated the theory that the amount of health behavior change progress a person makes over time is a function of the TTM stage of change that they are in. Determining the predictive power of staging classifications relative to actual behavior change can help health promotion program practitioners who use staging classifications from a Health Risk Assessment (HRA) to design and implement programs. This quantitative, quasi-experimental study employed a secondary database of archival HRA records. Baseline and posttest HRA data collected over a 12--13 month period as part of a corporate health promotion program were extracted from the database. The study population consisted of 2691 adults aged 18--65 from a large chemical company who had completed two online HRAs during the specified time period. Change in five health behaviors (fruit and vegetable consumption, physical activity, stress, weight management, high fat food consumption) was examined in relation to five stages of change after adjusting for differences in baseline behavior, by multiple analysis of covariance. No significant differences were found across stages for the mean change in fruit and vegetable consumption or physical activity. Stage of change for managing stress (F(4, 2685) = 2.89, p =.02), losing weight (F(4, 2685) = 2.46, p =.04), and decreasing high fat food intake (F(4, 2685) = 4.95, p < .001) had significant differences across stages for the corresponding health behavior change after one year. Although statistically significant, the stages of change accounted for less than 1% of the variance in health behavior change for these three variables. The use of HRA staging questions as a predictive measure for future behavior change was not supported by the present study. As this study was limited by the definitions of behavior and stage derived from the HRA under investigation, future research in the field would benefit from studies that use validated instruments to measure behavior and stage of change. |
