Table 1 Overview of data items about informal care and overview of (some of) the other themes collected in the second Lifelines follow-up questionnaire

Informal care data items in second Lifelines follow-up questionnaire

 - Type of care relationship with care recipient (e.g., spouse, parent, child, neighbour; multiple answers possible)

 - Intensity of caregiving (hours of household care a week, hours of personal care a week, hours of practical care a week)

 - Start date of caregiving (month/year)

 - Living together with the care recipient (yes/no)

 - Caregiver burden (Self-rated Burden Scale) [22, 23]

 - Caregiver satisfaction (modelled after the SRB)

 - Consent for participation in informal care add-on study (yes/no)

 (Some of the) other themes covered in the second Lifelines follow-up questionnaire

 - Psychosocial work environment (Copenhagen Psychosocial Questionnaire) [24, 25]

 - Health status (RAND-36 question 1, somatization subscale Symptom Check List) [26, 27]

 - Health care use

 - Living and social environment

 - Acute stress (List of Threatening Experiences) [28, 29]

 - Chronic stress (Long-term Difficulties Inventory) [30]

 - Personality (e.g., Goal adjustment scale) [31]

 - Lifestyle, including smoking, nutrition (Food frequency questionnaire), and physical activity (SQUASH) [32, 33]