Objective: In cardiovascular research, Type D personality (high negative affectivity and social inhibition) has been associated with a more than 3-fold increased risk of adverse health outcomes. This study examined the validity and clinical correlates of the Type D construct as assessed by the Type D Scale-14 (DS14) in type 2 diabetes patients.

Methods: 1553 primary care patients with type 2 diabetes were assessed for demographic, clinical, lifestyle and psychological characteristics in 2007. A subgroup (n=1012) completed the DS14 again 1 year later.

Results: The two-factor model of the Type D construct was confirmed in exploratory and confirmatory factor analyses; results were stable across gender. The Negative Affectivity (NA) and Social Inhibition (SI) subscales had adequate reliability in both men and women, as measured by Cronbach's alpha (NA=0.87, SI=0.83), lambda2 (NA=0.87/0.88, SI=0.84), corrected item-total correlations (NA 0.47-0.77, SI 0.34-0.72) and mean inter-item correlations (NA=0.50/0.51, SI=0.42). One year test-retest reliability using intraclass correlation coefficients was 0.64/0.63 for NA and 0.73/0.65 for SI. Type D and non-Type D patients did not differ in vascular history or physiological risk factors, but Type D women had a more sedentary lifestyle (p=.003). Type D patients experienced less social support and more stressful life events, loneliness, and more depressed mood, anhedonia and anxiety (p<.001 for most variables). These differences were clinically significant (Cohen's d>0.60 for most variables).

Conclusion: Type D personality can be reliably assessed in primary care patients with type 2 diabetes, and is associated with increased loneliness, stress and emotional distress in these patients.