Abstract 1144: Does Stage of Change Modify the Effectiveness of an Educational Intervention to Improve Diet?
Background: Effectiveness of educational interventions to affect positive lifestyle changes may differ based on participant readiness to change behavior. We aimed to evaluate whether effectiveness of a special intervention (SI) to improve diet among family members of CVD patients vs a control intervention (CI) was modified by readiness to reduce dietary saturated fat (SFA) based on the Transtheoretical Model Stages of Change.
Methods: Stage of change (precontemplation, contemplation, preparation, action, maintenance) was assessed by standardized questionnaire and diet was measured by full length Block 98 Food Frequency Questionnaire at baseline and 1 year in participants in the NHLBI sponsored Family Intervention Trial for Heart Health (n=501; 36% non white; 66% female). Therapeutic Lifestyle Change diet education was provided to each SI subject tailored to baseline stage of change to reduce dietary SFA. Linear regression was used to
evaluate the association between group assignment and stage of change on diet change from baseline to 1 year,
adjust for covariates and
test for interaction between group assignment and stage of change.
Results: Baseline SFA and cholesterol intakes were lower among those in maintenance stage vs others [(9.9% vs 11.2%; p<.0001) and (111.3 vs 129.1 mg/1000kcal; p=.0002) respectively]. Among participants in contemplation greater reductions in SFA (−2.1% vs +0.3%; p=.04) and cholesterol (−34.0 vs +32.6 mg/1000kcal; p=.01) were seen in the SI vs CI. There was a significant interaction between contemplation and SI group assignment on SFA change adjusted for confounders (p<.05); SI participants in contemplation had greater SFA reduction than non contemplators which was not observed in the CI. The SI was more likely than CI to achieve new adherence to a diet <10% SFA/<300mg cholesterol at 1 year among those not in maintenance stage (30% vs 14%; p=.01), but not among those in maintenance. CI participants were more likely than SI to revert to lower levels on the continuum of change from baseline to 1 year (17% vs 7%; p=.002).
Conclusion: The effectiveness of a targeted educational intervention to lower SFA varies by baseline stage of change. This may be important to consider in designing clinical and research dietary interventions.