All FIREA participants will be followed up by annual survey starting at 18 months before their statutory retirement date and continuing at least until 18 months post-retirement (n=7,774).

The mailed questionnaire covers areas that might change during the retirement transition, such as health behavior (physical activity, sedentariness, sleep quality and duration, napping, daytime sleepiness, smoking, alcohol consumption, weight), health status, mental health, functioning, pain, psychological well-being, social ties, as well as use of health care services. The questionnaire also covers questions related to employment situation of the spouse, social network and caregiving.

The survey data are linked to the high-quality national registers including detailed records of special reimbursements for severe and chronic illnesses, medicine purchases, granted rehabilitation, sickness absence, early retirement and statutory retirement, cancer morbidity, hospitalizations, occupational injuries and diseases, cause-specific mortality; work history over the life-course and periods of unemployment.