Individuals and illnesses as sources of perceived preventability

Perceived preventability of illness is an important predictor of health behaviour and response to illness. Yet, health experts remain largely unaware of the extent to which preventability attributions reflect characteristics of persons, illnesses and their interaction. Quantifying the sources of variance that compose illness preventability attributions may be especially useful for designing effective preventative health interventions. In the present study, we used generalisability theory to examine the sources of variance in illness preventability attributions. Undergraduate college students (N = 44) rated the personal preventability of 12 well-known physical illnesses. Preventability attributions were shown to most substantially reflect characteristics of illnesses (57.5% target effect). However, preventability attributions also strongly reflected interactions of individuals and illnesses (26.0% relationship effect). Characteristics of individuals were also significant, although they explained a relatively smaller amount of variance (7.1% perceiver effect). In general, these results suggest new directions for conceptualising theory and research on perceived preventability of illness.