Table 2 Overview of the themes measured in Lifelines ICAS

(a) Caregiving situation: type of care relationship; month and year of start of caregiving; living situation care recipient; participating care recipient in Lifelines.

(b) Health situation care recipient: reasons for care needs (cognitive problems/dementia, psychological problems, physical problems, intellectual problems, behavioural problems); list of (chronic) diseases and disorders [34]; current health situation (temporarily problems, chronical problems, dying)

(c) Health situation of caregiver: health-related quality of life (EQ-5D, EQ-VAS) [35]

(d) Caregiver activities besides caregiving: paid employment, household tasks, care for children living at home, voluntary work, leisure activities, reduction of activities due to caregiving responsibilities.

(e) Informal care tasks: total hours a week; hours a week per care tasks (household care, personal care, nursing care, emotional support and supervision, assistance with administrative/financial issues, assistance with outside activities)

(f) Support: support focused on caregiver (e.g. social work, caregiver support groups, (un)paid help with own household chores or care for own children, respite care), and support focused on care recipient (e.g., other informal caregiver/volunteer, paid/professional household or personal care, day care/treatment)

(g) Caregiving experiences: Caregiver Reaction Assessment (CRA) [36, 37], Self-rated burden scale (SRB) [22, 23], Positive Aspects of Caregiving scale (PAC) [38], Positive Experiences Scale (PES) [39], Satisfaction with caregiving (VAS scale, modelled after the SRB), relationship quality with care recipient (VAS scale, change since start of caregiving)

(h) Reasons for informal care provision: list of reasons for informal care provision, ranging from ‘out of love and affection’ and ‘satisfaction from caregiving’ to ‘no availability in care institution’ and ‘no one else is available’. Four domains can be identified: naturally/obviousness, preference for staying home, no alternatives, and relationships [40]

(i) Informal care and paid work: application of work arrangements, ability to combine informal care and paid work (VAS scale), change in work hours because of caregiving, satisfaction with employer (VAS scale), work arrangements applied by self-employed caregivers