Svansdottir et al. BMC Public Health 2012, 12:42 http://www.biomedcentral.com/1471-2458/12/42 such, been strongly associated with psychological comorbidity in cardiac patients, e.g. post-traumatic stress disorder [6], anxiety [7-9], depression [9,10], and vital exhaustion [11]. However, further research revealed that Type D personality is also associated with increased morbidity [12], mortality [13-15] and a poor quality of life [16] across diverse CVD patient groups, where it has been associated with a 3-fold increased risk of poor prognosis [17]. Several studies have demonstrated that the effect of Type D personality on adverse outcomes is independent of biomedical risk factors, such as hyper- tension [14,16] and disease severity, comprised by multi- vessel disease and left ventrical function [14,18]. With a prevalence of 25-38% in cardiac patients [14,19-21], Type D personality can potentially influence the prognosis and well-being of a substantial number of cardiac patients. It is still unclear what mechanisms link Type D per- sonality with poor clinical outcomes in CVD patients [22]. Mediating mechanisms may include both physiolo- gical and behavioral factors [13,23,24]. Recent findings have suggested that negative health-related behavior [22] and inadequate consultation behavior [25] may play a role in the behavioral factor vicinity. Individuals experi- encing psychological distress may for instance be more prone to use maladaptive coping styles, such as increased smoking and poor diet [26], which again can negatively impact the disease process. Further investiga- tions on how Type D personality influences the health of cardiac patients are needed, especially since such ana- lysis would provide clues for possible targets for inter- vention in these patients [13,14]. In addition, there is also a need for more cross-cultural investigations on Type D personality and its influence, since previous investigations have primarily focused on samples of Bel- gian and Dutch origin [27]. The aim for the present study was twofold: (1) to investigate the relationship of Type D personality with anxiety, depression and stress in Icelandic cardiac patients, and to explore whether this association is inde- pendent of indicators of disease severity; and (2) to investigate the relationship of Type D personality with certain health-related behaviors in these patients. Methods Participants The original participant sample consisted of 315 patients who underwent a coronary angiography at Landspitali- University hospital from January to May 2008. These patients were a part of a larger study, the “Risk factors, prognosis and success of medical procedures in patients undergoing coronary angiography at Landspitali-Univer- sity Hospital”, and were included in the current study because they answered additional questionnaires Page 2 of 10 measuring anxiety, depression and stress at baseline. Participants were first approached when hospitalized to the coronary care unit or upon arrival to the emergency ward. Follow-up assessments were administered with a phone call to participants in July 2008, approximately four months after discharge (M = 106 days, (SD 27.2 days)). A total of 268 patients (85%) completed the fol- low-up, and were included in the final study sample. Of the excluded 47 patients (15%), six patients (2%) were deceased, one patient lived abroad and was therefore not included in follow-up, three individuals (1%) refused to participate in the follow-up and the remaining 37 (11%) could not be reached. The follow-up group did not differ in age from the patient group not reached at follow-up (M = 62.8 years, (SD 10.5) versus M = 65.4 years (SD 9.3), t(313) = 1.56, p = 0.12). The study proto- col was approved by the medical ethics committee of The National Bioethics Committee in Iceland. The study was conducted conform to the ethical tenets developed by the World Medical Association, as espoused in the Declaration of Helsinki. All patients provided written informed consent. Demographics Information concerning gender and age was gathered from medical records, while data concerning educational level (elementary, higher education (secondary or uni- versity)) and family status (living alone/widowed, mar- ried/living with partner) were collected by self-report from participants. Clinical variables measured at baseline Information regarding disease classification, traditional coronary artery disease (CAD) risk factors, and disease severity were retrieved from patients’ medical records. Information on disease status was classified as follows: CAD, myocardial infarction (MI), arrhythmias, heart valve disease and heart failure. Traditional CAD risk factors were defined in the following way: smoking (yes, no); hypertension (no hypertension treatment, current hyper- tension treatment); on blood-lipid lowering medication (no, yes); diabetes (no, yes); and overweight (body mass index, BMI). Disease severity was defined by a) the num- ber of coronary arteries affected by CAD (0 or 1 artery versus ≥ 2 arteries), and b) cardiac history (previous percu- taneous coronary intervention (PCI), previous MI, and/or a previous coronary artery bypass surgery (CABG)). Measures All participants were administered the Icelandic versions of the Type D scale (DS14) [19], the Hospital Anxiety and Depression Scale (HADS) [28], and the Perceived Stress Scale (PSS) [29] at baseline, when hospitalized for a coronary angiography.