Introduction In the current COVID-19 pandemic, disease diagnosis is essential for optimal management and timely isolation of infected cases in order to prevent further spread. The aim of this study was to systematically review the assessment of risk and model the predictors of mortality in COVID-19 patients. Methods A systematic search was conducted of PubMed, Scopus, Embase, Google Scholar, and Web of Science databases. Variables associated with hospital mortality using bivariate analysis were included as potential independent predictors associated with mortality at the p <0.05levels. Results We included 114 studies accounting for 310,494 patients from various parts of the world. For the purpose of this analysis, we set a cutoff point of 10% for the mortality percentages. High mortality rates were defined as higher than 10% of confirmed positive cases and were given a score of two, while low mortality percentage (<10%) was assigned to the score of one. We then analyzed the associations between 72 variables and the observed mortality rates. These variables included a large range of related conditions such as demographics, signs and symptoms and related morbidities, vital signs, laboratory findings, imaging studies, underlying diseases, and the status of countries' income based on United Nation's classifications. Conclusion Findings suggest that older age, hypertension, and diabetes mellitus conferred a significant increased risk of mortality among patients with COVID-19. In the multivariate analysis, only diabetes mellitus demonstrated an independent relationship with increased mortality. Further studies are needed to ascertain the relationship between possible risk factors with COVID-19 mortality.

Introduction It is reported that coronavirus disease (COVID-19) can affect the sense of smell and taste of infected people. The pathobiology of this virus is still incompletely known, and it is therefore important to explore the impact of COVID-19 infections on olfactory and gustatory functions. We aimed to review current evidence on olfactory and gustatory dysfunctions caused by COVID-19. Methods This study was a narrative review performed in 2020 to investigate the olfactory and gustatory dysfunctions of the COVID-19. We searched eight keywords in six databases to determine the related documents on the main objective of the study. To discover studies meeting the inclusion criteria, the authors screened the titles and abstracts of the identified articles. The appropriate studies were included and their results were discussed to make the final selection. Results We have studied 24 current articles on the olfactory and gustatory dysfunctions due to COVID-19. A review of current studies has shown that we have a surge in the spread of olfactory and gustatory dysfunctions that happened during the epidemic of COVID-19 infection. Most studies (95.8%) have confirmed the symptoms of anosmia in patients with SARS-CoV-2 infection. A review of current studies showed that, in addition to anosmia, evidence of ageusia and dysgeusia (parageusia) was also seen in patients with COVID-19. Conclusion The results of our study support recent reports that SARS-CoV-2 may infect oral and nasal tissues and cause olfactory and gustatory dysfunctions. These findings may aid future research on the diagnosis, prevention, and treatment of COVID-19 consequences.

Background and Aims: Older people have higher rates of comorbidities and may experience more severe inflammatory responses; therefore, are at higher risk of death. Herein, we aimed to systematically review the mortality in coronavirus disease 2019 (COVID-19) patients and its predictors in this age group.Methods: We searched PubMed, Web of Science, and Science Direct using relevant keywords. Retrieved records underwent a two-step screening process consisting of title/abstract and full-text screenings to identify the eligible studies.Results: Summarizing findings of 35 studies demonstrated that older patients have higher mortality rates compared to the younger population. A review of articles revealed that increasing age, body mass index, a male gender, dementia, impairment or dependency in daily activities, presence of consolidations on chest X-ray, hypoxemic respiratory failure, and lower oxygen saturation at admission were risk factors for death. High D-dimer levels, 25-hydroxy vitamin D serum deficiencies, high C-reactive protein (≥5 mg/L) levels plus any other abnormalities of lymphocyte,