Study design and sample

A longitudinal design was used to explore the predictive association between PTSD and HRQL in hospitalized cardiac patients after a 12-month follow-up. This study followed cardiac patients consecutively admitted to cardiology units at four major hospitals in Nablus, Palestine. The recruitment and procedures of the study and data from the baseline study have been described in detail elsewhere [18]. To be eligible for the study, patients were required to be between 30 to 80 years old and have clinically diagnosed CHD, MI, angina, heart failure, or any other cardiac disease. Patients were recruited for the initial baseline assessment within one week of hospitalization (range 1–7 days) between March, 2017 and November, 2017. With a participation rate of 96∙0%, a total of 1053 patients were included in the study. Thirty four patients were excluded from the baseline analysis and follow-up due to incomplete data. A follow-up assessment was conducted approximately one year after enrollment in the study between June, 2018 and December, 2018 (Fig 1). Ethical approval for the study was obtained from the Ethics Committee of Nordwest-und Zentral Schweiz (EKNZ) (Project ID: 2017–00235) in Basel, Switzerland, and the Institutional Review Board (IRB) committee at An-Najah National University in Nablus, Palestine. All participants provided a written informed consent at baseline and follow-up.