Associations between illness belief dimensions, illness clusters, health and well-being indicators among adults with type 2 diabetes: findings from the PREDICT cohort study.

OBJECTIVE: The common sense model posits that illness beliefs form distinct clusters and these are associated with self-care and well-being, but few studies have examined this. Therefore, we tested this hypothesis in a large diabetes cohort. DESIGN: Participants of the PREDICT cohort study completed validated measures of illness beliefs, depressive symptoms, anxiety symptoms, diabetes distress, self-care and provided biomedical data, including HbA1c at baseline recruitment. RESULTS: One thousand five hundred and eighty-six participants with type 2 diabetes (37% female, mean 65 years old, median 11 years diabetes duration), were found to form four clusters: Resigned (20%), Adapters (28%), Symptomatic (28%), Acute (17%). Adapters had lower BMI, HbA1c, diastolic blood pressure, cholesterol, diabetes distress, depressive and anxiety symptoms and had higher HDL and were more active than all other clusters. The Symptomatic cluster were diagnosed younger, had diabetes longer, more likely to be taking insulin, have had foot ulcers/amputation, had more depressive and anxiety symptoms with greater diabetes distress but drank less alcohol. Regression analysis indicated illness beliefs were more strongly associated, with self-care, health and well-being indicators than cluster membership. CONCLUSIONS: Adults with type 2 diabetes can be categorised into distinct clusters of illness beliefs, but individual beliefs are better predictors of self-care and well-being.