Background: Type D (distressed) personality and medication nonadherence have been associated with poor health outcomes. Type D personality is associated with poor medication adherence in patients with coronary artery disease. However, the relationship between type D personality and medication adherence in patients with heart failure (HF) remains unknown.

Purpose: Therefore, the goal of this study was to examine the association between type D personality and medication adherence in patients with HF.

Method: This was a sub-analysis of baseline data from a randomized controlled trial with 84 patients with HF in the USA. Demographic, clinical, and psychological data were collected at baseline by interview, questionnaires, and medical record review. Type D personality was assessed using the Type D Personality Scale (DS14). Medication adherence was measured using both objective (Medication Event Monitoring System, MEMS) and self-reported (Morisky Medication Adherence Scale, MMAS-4) measures. Patients started medication adherence monitoring with the MEMS bottle at baseline and is used continuously for a month. Multiple regressions were used to explore the relationships between type D personality and medication adherence while adjusting for demographic, clinical, and psychological factors.

Results: Patients with type D personality were more likely to have poor medication adherence. Type D personality was associated with medication adherence before and after adjusting for covariates when it was analyzed as a categorical variable. However, type D personality was not associated with medication adherence when analyzed as a dimensional construct. Negative affectivity, a component of type D personality, was associated with medication adherence.

Conclusion: As a dimensional construct, type D personality may not reflect the components of the personality associated with poor outcomes. Negative affectivity was associated with medication adherence in patients with HF. Interventions aiming to improving/enhancing medication adherence need to take into account patients with the negative affectivity component of type D personality who are at higher risk for poor medication adherence, which may lead to adverse health outcomes.