Self-efficacy and multiple illness representations in older adults: a multilevel approach.

Objectives: The Common-Sense Model assumes that individuals form subjective representations about their illnesses, which in turn guide cognitive and behavioural responses. This assumption is complicated in individuals with multimorbidity, and it is an open question to which degree illness-specific and person-level factors determine the representations of specific illnesses. This study examines the structure and interrelations of illness representations in multimorbidity employing a hierarchical framework based on Cognitive Theory.

Methods: Multiple illness representations were assessed in 305 people aged 65 and older using two Brief Illness Perception Questionnaires. Multilevel modelling was used to explore the relations between illness representations and to explain how two illness-specific representations--personal control and treatment control--were determined by a person-level factor, self-efficacy.

Results: Self-efficacy had significant main (B = 0.29; p < 0.01 for personal control; B = 0.19; p < 0.05 for treatment control) and interaction effects (B = 0.38; p < 0.01 personal control on self-efficacy × timeline; B = -0.31; p < 0.05 treatment control on self-efficacy × coherence).

Conclusions: This study suggests that illness-specific representations of older people with multimorbidity are a product of both illness-specific and person-level factors, such as self-efficacy. Strengthening individual self-efficacy may improve illness controllability regardless and on top of illness-specific information.