BackgroundPosttraumatic Stress Disorder (PTSD) is a severe anxiety disorder occurred due to past adverse experiences. Several researches have demonstrated that PTSD is quite common among patients discharged from critical care unit.ObjectivesThis study aimed to investigate the prevalence of PTSD and its related factors among patients discharged from critical care units in Kashan, Iran, during 2014.Patients and MethodsA descriptive prospective study was performed on 332 patients admitted to critical care units of Kashan Shahid Beheshti Hospital using a convenience sampling method. Data were collected in wards during hospitalization and one month after their discharge from hospital using questionnaires on demographic, medical information and PTSD Checklist (PCL). The PCL scores of 45 or more were considered as PTSD. Data were analyzed using chi-square, t-test, Mann-Whitney U and logistic regression.ResultsFrom a total of 332 patients, 160 cases (48.2%) had PTSD and the mean total PCL score in participants was 44.24 ± 19.89. There was a significant difference between the total score of PTSD and its domains in patients with and without PTSD. the univariate analysis showed a significant association between PTSD and increasing age, increased length of hospital stay, more children, having additional comorbidities, unemployed, use of mechanical ventilation (P < 0.001), drug abuse (P = 0.003) and single patients (P = 0.028). However, there was no significant association between PTSD and gender, type of the critical care unit, level of education and admission due to trauma. However, in multivariate analysis using logistic regression, factors associated with PTSD were older age of the participants, use of mechanical ventilation having additional comorbidities, unemployed (P<0.001) and being single (P=0.04)ConclusionsPrevalence of PTSD is high among patients discharged from ICUs and some medical individual factors such as elderly, unemployed, being single, using mechanical ventilation and pre-existing diseases are risk factors. Therefore, it is recommended to perform appropriative educational plan for these patients to reduce the risk of PTSD.