Background:The COVID-19 disease has worse outcomes in individuals with underlying diseases and elderly individuals. Therefore, identifying COVID-19 risk perception and its related factors and outcomes in vulnerable groups is essential for the health system. Objectives: This study aimed to determine COVID-19 risk perception, its related factors, and outcomes in vulnerable groups (individuals with underlying diseases, smokers, opioid addicts, the elderly, and pregnant women). Methods: This systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The search was carried out using the keywords "Risk perception" and "COVID-19" in PubMed, Scopus, Science Direct, SID, Proquest, and Magiran databases in the period from 2019 to July 3, 2021. The quality of selected studies was checked by two authors independently according to Newcastle-Ottawa Scale adapted for cross-sectional. Results: In the initial search, 640 articles were found, of which 56 remained in the screening phase. Then, the full text of 56 articles was studied. Eventually, based on the inclusion and exclusion criteria of the articles, 8 articles were reviewed. This systematic review showed that suffering from an underlying disease, more anxiety, younger age, and female gender are associated with higher COVID-19 risk perception. The outcomes of COVID-19 risk perception were higher COVID-19 risk perception, delayed treatment sessions, increased anxiety and fear, increased ineffective safety behaviors, and greater compliance with health protocols. Conclusion:Creating sensitivity and proper COVID-19 risk perception is necessary to follow health protocols, but high COVID-19 risk perception can endanger vulnerable groups' mental and physical health. Besides, reducing the sensitivity of vulnerable groups toward COVID-19 can expose them to the disease.

Context: COVID-19 results in an imbalance between procoagulant and anticoagulant homeostatic mechanisms that could be complicated with thrombotic events. In β-thalassemia patients, the presence of comorbidities, iron overload, adrenal hypofunction, splenectomy, and chronic hypercoagulable state might increase the susceptibility to COVID-19 and its severity. Evidence Acquisition: The search was conducted in PubMed, Web of Science, and Scopus databases for the key terms of β-thalassemia/thalassemia and COVID-19 until July 2021. Results: The survey of published observational studies (mostly multicenter and case reports) indicated a lower prevalence of COVID-19 in β-thalassemia patients compared with the general population, as well as mild to moderate COVID-19 in these patients, especially in those without comorbidity. β-Thalassemia children were susceptible to COVID-19 but with less severity compared to adults. There is no report of pulmonary embolism and thrombotic events in β-thalassemia patients with COVID-19; however, coagulation abnormality and pulmonary microembolism have been found in these patients. Conclusions: Findings could be interpreted by the presence of high hemoglobin F (HbF) levels, the advantage of hydroxyurea (HU) therapy, splenectomy, and iron chelation therapy in these patients. However, due to the low sample size and studying mainly young patients, the results should be interpreted with caution, and it still needs more studies with a larger sample size to confirm these findings.

Background: Coronaviruses are a large family of RNA viruses, which range from the common cold virus to the causative agent of more severe diseases. Coronavirus was declared a pandemic in December 2019 in Wuhan, China. Iran has been an endemic zone for the spread of the coronavirus since the outset of this global epidemic and has remained among the countries largely affected by high rates of the disease. Objectives: The present study aimed to investigate the range of the chest computed tomography (CT) scan findings among the hospitalized patients with COVID-19 in Kermanshah, Iran during March-April 2020 to contribute to the accurate diagnosis of the infected patients. Methods: The sample population consisted of 286 hospitalized patients diagnosed with or suspected of the coronavirus disease. Chest CT-scan images and clinical data were reviewed, and their correlation was analyzed. Results: In total, 176 patients (61.53%) were male, and 110 (38.47%) were female. The mean age of the patients was 56 years. Polymerase chain reaction (PCR) results showed that 35.31% of the cases had coronavirus, while the results were negative in 64.69% of the cases. In addition, the CT-scan findings indicated 77.27% abnormal and 22.73% normal chest CT-scans. Among the patients, 75.87% recovered completely, and 18.53% died. The major CT abnormalities were diffuse ground-glass opacification (35.66%), peripheral ground-glass opacification (bilateral; 21.33%), and a combination of diffuse and peripheral ground-glass lesions (18.88%). The consolidation lesion of one lobe was detected in 16 patients, and the consolidation lesion of more than one lobe was observed in 40 patients. Conclusions: According to the results, the most common chest CT-scan findings in COVID-19 include diffuse ground-glass opacification, peripheral ground-glass opacification (bilateral), central ground-glass opacification (bilateral), a combination of diffuse and peripheral ground-glass opacification, a combination of central and peripheral ground-glass opacification, the consolidation lesion of one lobe, and the consolidation lesion of more than one lobe. Furthermore, significant correlations were observed between the CT-scans and the main clinical symptoms, while no significant correlations were denoted between the chest CT-scan and PCR results.