Cost-effectiveness of an individually-tailored long-term worksite health promotion programme on physical activity and nutrition

Objective: To evaluate the cost-effectiveness of an individually-tailored long-term worksite health promotion programme on physical activity and nutrition. Study design: Cluster randomized controlled trial with 700 workers in clusters with a maximum of 20 workers and measurements at baseline, 12, and 24 months (2 * 350). Study population: workers in companies who are offered a worksite health promotion programme (WHPP). Standard WHPP (usual care): health check with a one-off biometric assessment and advice on attainable goals for improvement in daily physical activity and fruit & vegetables intake. In addition, single workshops are offered to selected participants. Intervention: The intervention adds during 1 year a personal health portal on internet with (1) personal results of biometry, (2) tailored advice on physical activity and diet to the physical health measures (biometry) and individual characteristics of the participant, (3) continuous support and feedback by monthly questions and answers through e-mails by a personal coach, and (4) overview of progress in self-reported behaviour and body mass index. We hypothesize that the Health Portal will substantially increase adherence and sustainability. Primary outcome measures (impact evaluation): compliance with healthy lifestyle (yes/no) for physical activity (30 min moderate activity on 5 days per week) and fruit and vegetables consumption (2 servings and 200 gr per day, respectively), assessed by validated questionnaires at 0, 12, and 24 months. Secondary outcome measures (effect evaluation): risk for cardiovascular disease (Score European guidelines), cholesterol, blood pressure, body mass index, body fat percentage, and submaximal VO2-max (cardiorespiratory fitness), measured at 0 and 24 months. Analysis: intention-to-treat with last available information carried forward to missing data. A multilevel linear regression model with repeated measurements for continuous outcomes and hierarchical logistic regression for dichotomous outcomes. The effect of self-efficacy, environmental determinants, lack of adherence and drop-out on impact and effect measures will be evaluated. Economic evaluation: a cost-effectiveness analysis with cost-effectiveness ratios on recommendations on nutrition and physical activity (impact measures) and on general health (SF-12) and predicted cardiovascular mortality (Score measure). The costs include direct costs of medical utilization and indirect costs of productivity loss at work due to health problems and indirect costs of sickness absence. A sensitivity analysis will be performed on the distribution of individual cost-effectiveness ratios. Time schedule: 4 year study with 2 year follow-up of participants and 1.5 year intake period.