Type D personality predicts poor medication adherence in myocardial infarction patients.

Type D personality, the combination of negative affectivity (NA) and social inhibition (SI), is an emerging risk factor in cardiovascular disease. This study aimed to examine one possible behavioural mechanism to explain the link between Type D and ill-health. It was hypothesised that Type D personality would predict medication adherence in myocardial infarction (MI) patients. In a prospective study, 192 MI patients (54 females and 138 males) completed measures of Type D personality and provided demographic and medical information 1 week post-MI, and then 131 patients went on to complete a self-report measure of medication adherence 3 months post-MI. It was found that Type D personality predicts adherence to medication, after controlling for demographic and clinical risk factors. Critically, the constituent components of Type D, NA and SI, interact to predict medication adherence, after controlling for the effects of each component separately. Poor adherence to medication may represent one mechanism to explain why Type D cardiac patients experience poor clinical outcome, in comparison to non-Type D patients. Interventions, which target the self-management of medication, may be useful in these high-risk patients.