Relation of Personality Traits in Patients with Oral Anticoagulant Therapy to Attitudes towards Treatment with Vitamin-K Antagonists.

Abstract 4183

Stable anticoagulation as determined by the international standardized ratio (INR) remains difficult despite increasing knowledge on pharmacogenetics of vitamin K antagonists (VKA) and improved therapeutic approaches. We hypothesised that personality traits of patients may influence attitudes towards treatment VKA.

Thirty patients treated with VKA for more than one year completed a widely used personality inventory (Freiburger Persönlichkeitsinventar, FPI-R) and a questionnaire referring to adherence, safety and anxiety problems during anticoagulant therapy after written informed consent. Indications for anticoagulation were venous thromboembolism (n=22) and atrial fibrillation (n=8). Correlations between FPI-R factors and items of the anticoagulant therapy questionnaire were analysed by means of the chi-square test.

Patients understanding the concept of VKA therapy and being open for modifications of the dose of VKA, they are more emotional and less excitable (p=0.008 and 0.009), respectively. Patients who felt burdened at initiation of VKA therapy were less achievement-oriented (p=0.02). Those who forget sometimes the intake of the VKA are more self-inhibited (p=0.004) and more socially oriented (p=0.007). Patients following a diet during anticoagulant therapy, are more concerned about general health (p=0.009) and are more socially orientated (p=0.05). Those who like to eat vitamin-K containing vegetables are more excitable (p=0.01). Importantly, patients being afraid of thrombotic events are more aggressive (p=0.01) and have more physical complaints (p=0.02). Those being afraid of bleeding complications, are more aggressive (p=0.046), more demanded (p=0.05) and more intraverted (p=0.004).

Personality traits appear to influence the therapy with VKA manifold. Fear of thrombotic or bleeding events during anticoagulant therapy can be identified by specific personality traits.