Statistically modelling the relationships between Type D personality and social support, health behaviors and symptom severity in chronic illness groups

OBJECTIVE: The study aimed to develop a predictive model of how Type D personality influences health behaviours, social support and symptom severity and assess its generalisability to a range of chronic illnesses. DESIGN: Participants were classified as either healthy (n = 182) or having a chronic illness (n = 207). Participants completed an online survey measuring Type D and a range of health-related variables. Chronic illness participants were classified as having either a functional somatic syndrome (i.e. chronic fatigue syndrome or fibromyalgia), where the underlying pathological processes were unclear, or illnesses such as type 2 diabetes, osteoarthritis or rheumatoid arthritis, where the causes are well understood. MAIN OUTCOME MEASURES: Outcome measures were health behaviours, social support and both physical and psychological symptoms. RESULTS: The rate of Type D was higher in chronic illness participants (53%) than in healthy controls (39%). Negative affectivity (NA) and social inhibition (SI) both correlated with outcome measures, although NA was generally the stronger predictor. Using NA and SI as independent subscales led to superior prediction of health outcomes than using categorical or continuous representations. CONCLUSION: Findings suggest that the relationship between Type D and health outcomes may generalise across different chronic illnesses.