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

Abstract

Objective: The study aimed to develop a predictive model of how Type D personality influences health behaviors, social support, and symptom severity and assess its generalizability 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 behaviors, 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 generalize across different chronic illnesses.

A Critical Analysis of the Assumptions of Type D Personality: Comparing Prediction of Health-Related Variables with the Five Factor Model

“…Categorical Type D was also only able to improve prediction, albeit modestly, for one of the four outcomes, over and above continuous subscales. Consistent with past research (Atherton et al, 2014;Horwood et al, 2016;Kelly-Hughes et al, 2014), results also showed no evidence of interactive effects of negative affectivity and social inhibition. Thus, while interactive effects are one means of personality types providing superior prediction to interval scales (Asendorpf, 2003), this does not appear to be the case when using either the interaction of interval subscales or when using categorical Type D.…”

“…Research shows that dichotmizing an interval scale reduces correlations (Aguinis, Pierce, & Culpepper, 2009;Rucker, McShane, & Preacher, 2015). Demonstrating this general point, Horwood et al (2016) found that treating Type D as a dichotomous variable reduced predictive validity relative to a continuous representation of Type D.…”

“…Given the overlap of the Big Five traits of neuroticism (+) and extraversion (-) with negative affectivity and social inhibition respectively, if Type D theory was correct, then we might also expect interaction effects to be present between neuroticism and extraversion. There is almost no evidence that traits such as neuroticism and extraversion have interactive effects (Atherton et al, 2014), nor is there evidence that the two subscales of negative affectivity or social inhibition have interactive effects in predicting health-related variables (Horwood et al, 2016;Kelly-Hughes et al, 2014).…”

“…The Type D personality construct implies that personality types are meaningful and useful, traits have interactive effects, and that the narrow traits of negative affectivity and social inhibition are more relevant than broad traits such as neuroticism and extraversion. While a few studies have challenged the assumptions of Type D personality regarding its status as a categorical variable (Ferguson et al, 2009;Howard & Hughes, 2012;Kelly-Hughes, Wetherell, & Smith, 2014) and its interactive effects (Horwood et al, 2016;Kelly-Hughes et al, 2014), almost no research has examined the ability of Type D personality to predict health-related variables in comparison to a comprehensive hierarchical framework of personality based on the Big Five. Thus, the present study sought to address these issues by comparing the predictive validity of various representations of Type D personality with the Five-Factor Model (Costa & McCrae, 1992).…”

“…Theory and research suggests that Type D personality is a risk factor for increased morbidity and mortality in several chronic illnesses including coronary artery disease (Svansdottir et al, 2013) and type 2 diabetes (Nefs et al, 2015). Various mechanisms have been proposed to explain the relationship between Type D and chronic illness, including greater levels of negative health behaviors (Horwood, Anglim, & Tooley, 2016), lower levels of social functioning (Grande, Romppel, Michal, & Brähler, 2014), and a tendency to adopt poorer coping strategies (Booth & Williams, 2015).…”