A randomized trial of the IMPACT worksite cholesterol reduction program.
To evaluate the incremental effectiveness of a worksite cholesterol control management program when added to an established, comprehensive health promotion program at the worksite, we conducted a randomized, controlled trial including both blue- and white-collar employees at four geographically dispersed worksites. One hundred twenty-seven employees with serum cholesterol levels of 240 mg/dL or greater were assigned to receive an enhanced intervention program (the IMPACT program) while 125 were assigned to a regular screening and referral group, which included a comprehensive worksite health promotion program. One hundred eighteen program and 116 control subjects had one-year follow-up measures recorded. We used venipuncture specimens to obtain standardized baseline and follow-up cholesterol measures. Program subjects experienced a mean decline of 16.6 mg/dL as compared to a decline of 10.0 mg/dL in control subjects. The crude intergroup difference was 6.6 mg/dL (95% confidence internal [CI] = 1.1, 14.3), while the adjusted difference was 6.9 mg/dL (95% CI = 0.5, 14.3). Neither difference was significant at the .05 level. The percentage of program subjects who reduced their cholesterol level to below 240 mg/dL (36%) was significantly greater than the corresponding percentage among control subjects (21%). The enhanced worksite cholesterol control program provided incremental benefit in the percentage of individuals with elevated cholesterol in a population already exposed to a comprehensive worksite health promotion program that includes regular cholesterol screening, referral, and education activities.