Impact of Electron Beam Tomography, With or Without Case Management, on Motivation, Behavioral Change, and Cardiovascular Risk Profile: A Randomized Controlled Trial

Abstract

CONTEXT: Although the use of electron beam tomography (EBT) as a motivational tool to change behavior is practiced, its efficacy has not been studied. OBJECTIVE: To assess the effects of incorporating EBT as a motivational factor into a cardiovascular screening program in the context of either intensive case management (ICM) or usual care by assessing its impact over 1 year on a composite measure of projected risk. DESIGN: Randomized controlled trial with a 2 x 2 factorial design and 1 year of follow-up. SETTING AND PARTICIPANTS: A consecutive sample of 450 asymptomatic active-duty US Army personnel aged 39 to 45 years stationed within the Washington, DC, area and scheduled to undergo a periodic Army-mandated physical examination were enrolled between January 1999 and March 2001 (mean age, 42 years; 79% male; 66 [15%] had coronary calcification; mean [SD] predicted 10-year coronary risk, 5.85% [3.85%]). INTERVENTIONS: Patients were randomly assigned to 1 of 4 intervention arms: EBT results provided in the setting of either ICM (n = 111) or usual care (n = 119) or EBT results withheld in the setting of either ICM (n = 124) or usual care (n = 96). MAIN OUTCOME MEASURE: The primary outcome measure was change in a composite measure of risk, the 10-year Framingham Risk Score (FRS). RESULTS: Comparing the groups who received EBT results with those who did not, the mean absolute risk change in 10-year FRS was +0.30 vs +0.36 (P =.81). Comparing the groups who received ICM with those who received usual care, the mean absolute risk change in 10-year FRS was -0.06 vs +0.74 (P =.003). Improvement or stabilization of cardiovascular risk was noted in 157 patients (40.2%). In multivariable analyses predicting change in FRS, after controlling for knowledge of coronary calcification, motivation for change, and multiple psychological variables, only the number of risk factors (odds ratio, 1.42; 95% confidence interval, 1.16-1.75 for each additional risk factor) and receipt of ICM (odds ratio, 1.62; 95% confidence interval, 1.04-2.52) were associated with improved or stabilized projected risk. CONCLUSIONS: Using coronary calcification screening to motivate patients to make evidence-based changes in risk factors was not associated with improvement in modifiable cardiovascular risk at 1 year. Case management was superior to usual care in the management of risk factors.