Validity of the Type D personality construct in Danish post-MI patients and healthy controls

Type D personality has been associated with increased risk of depression, vital exhaustion, social alienation, a higher number of reinfarctions, and higher mortality rates in patients with established coronary artery disease (CAD) independent of traditional biomedical risk factors. The construct was developed in Belgian cardiac patients, but little is known about its applicability in other nationalities. The objectives of the present article were to cross-validate the Type D Personality Scale-16 (DS16) in a Danish sample of patients with a first myocardial infarction and a random sample of healthy controls, and to investigate whether Type D is associated with posttraumatic stress disorder (PTSD).

A questionnaire was given to 112 consecutive patients with a first myocardial infarction 4 to 6 weeks post infarction, and to 115 healthy controls selected randomly from the general population.

The two-factor structure of the DS16 and the internal consistency of the Negative Affectivity (alpha=.83) and Social Inhibition (alpha=.76) subscales were confirmed. The construct validity of the DS16 was confirmed against scales that measure similar constructs, and the discriminant validity of the DS16 against measures of psychopathology. In a pooled sample of patients and healthy controls, comparison of both groups confirmed that Type D may be conceptualised as a marker of general emotional distress, with Type D persons scoring higher on depression, anxiety, and the PTSD symptom clusters arousal and avoidance compared with non-Type D persons. A regression analysis run in two steps showed that the inclusion of Type D in the model lead to an improvement in the level of prediction of PTSD above and beyond a model that included gender, age, MI, neuroticism, and extroversion. Type D (OR=4.46; 95% CI: 1.36 to 14.64), diagnosis of MI (OR=4.03; 95% CI: 1.43 to 11.35), and neuroticism (OR=1.32; 95% CI: 1.13 to 1.53) were independently associated with PTSD, adjusting for all other variables.

These findings indicate that the Type D construct is equally applicable in Danish patients with CAD, and that Type D is associated with PTSD.