Psychometric properties of a scale to measure investment in the sick role: the Illness Cognitions Scale

Rationale, aims and objectives A person's beliefs about their illness may contribute to recovery and prognosis. Some degree of acceptance of illness and its impact is necessary to integrate the presence of a chronic disorder into one's lifestyle and adhere to necessary components of illness management; however, some individuals can become stuck and have difficulty adjusting out of the sick role. Inventories exist to measure illness cognitions, attitudes and behaviours as they relate to hypochondria and psychosomatic illness, but there is no extant measure of sick role inertia. We describe the psychometric properties of a new scale, the Illness Cognitions Scale (ICS), a metric of investment in the sick role. Methods The ICS was administered to 97 individuals with bipolar or schizoaffective disorder, and the psychometric properties of the scale measured. Dimensionality was assessed using Principal Components Analysis with Oblimin rotation. Results The scale has a strong internal consistency, with a Cronbach's alpha of 0.858. Results of a factor analysis suggested the presence of one main factor, with three other smaller, related sub-factors, capturing aspects of maladaptive illness beliefs. Conclusion The ICS is a 17-item, internally validated scale measuring difficulty adjusting out of the sick role. The scale predominantly measures a single construct. Further research on external validity of the ICS is required as well as determination of the clinical significance and patient acceptability of the scale.