Figure 1

Illustration of two models. Model 1: Bifactor model: 1 general factor functioning and 4 subgroup factors: physical functioning (PF; 10 items), ADL^* (A; 5 items), IADL (I; 7 items) and participation (P; 6 items) Model 2: Combination of a bifactor model: 1 general factor functioning and 3 subgroup factors: physical functioning (PF; 10 items), ADL^* (A; 5 items), IADL (I; 7 items) and a separate but correlated factor participation (P; 6 items) ^*item A6 (eating) is excluded from the models.