Figure 1: Study flow. 2245 employees were divided by birthdates in an early and late invitation group. Early invitees who participated in the HRA program (Early participants) were additionally invited for follow-up measurements one year after their HRA completion. At that same moment the late invitation group was invited for participation in the HRA program. The primary outcome was the change in lifestyle parameters between baseline and follow-up. To check for a possible background effect of increased health consciousness due to program introduction at the worksite, baseline variables between early and late participants were compared. Non-response bias was checked by comparing baseline variables of follow-up attendees (142) and non-attendees (226).