Effects of Smoking on COVID-19 Management and Mortality: An Umbrella Review.

Introduction: Smoking status appears to lead to a poor prognosis in COVID-19 patients. However, findings from the studies conducted on this topic have not been consistent, and further exploration is required. Methods: The objective of this umbrella review was to examine the effects of smoking on COVID-19 management and mortality. Online databases that included PubMed, Embase, Scopus, and Web of Science were searched using relevant keywords up to July 27, 2022. Articles were restricted to the English language, and the PRISMA protocol was followed. Results: A total of 27 systematic reviews, published from 2020 to 2022, were included. Individual studies included in the systematic reviews ranged from 8 to 186, with various population sizes. The consensus from the majority of systematic reviews was that COVID-19 smoker patients experience greater disease severity, disease progression, hospitalization rate, hospital admission duration, mechanical ventilation, ICU admission, and mortality rate. Conclusions: COVID-19 patients with a history of smoking (current and former) are vulnerable to adverse hospital outcomes and worse COVID-19 progression. Effective preventive and supportive approaches are required to decrease the risk of COVID-19 morbidity and mortality in patients with a history of smoking.

Estimating Methods of the Undetected Infections in the COVID-19 Outbreak: A Systematic Review.

INTRODUCTION: The accurate number of COVID-19 cases is essential knowledge to control an epidemic. Currently, one of the most important obstacles in estimating the exact number of COVID-19 patients is the absence of typical clinical symptoms in a large number of people, called asymptomatic infections. In this systematic review, we included and evaluated the studies mainly focusing on the prediction of undetected COVID-19 incidence and mortality rates as well as the reproduction numbers, utilizing various mathematical models. METHODS: This systematic review aims to investigate the estimating methods of undetected infections in the COVID-19 outbreak. Databases of PubMed, Web of Science, Scopus, Cochrane, and Embase, were searched for a combination of keywords. Applying the inclusion/exclusion criteria, all retrieved English literature by April 7, 2022, were reviewed for data extraction through a two-step screening process; first, titles/abstracts, and then full-text. This study is consistent with the PRISMA checklist. RESULTS: In this study, 61 documents were retrieved using a systematic search strategy. After an initial review of retrieved articles, 6 articles were excluded and the remaining 55 articles met the inclusion criteria and were included in the final review. Most of the studies used mathematical models to estimate the number of underreported asymptomatic infected cases, assessing incidence and prevalence rates more precisely. The spread of COVID-19 has been investigated using various mathematical models. The output statistics were compared with official statistics obtained from different countries. Although the number of reported patients was lower than the estimated numbers, it appeared that the mathematical calculations could be a useful measure to predict pandemics and proper planning. CONCLUSION: In conclusion, our study demonstrates the effectiveness of mathematical models in unraveling the true burden of the COVID-19 pandemic in terms of more precise, and accurate infection and mortality rates, and reproduction numbers, thus, statistical mathematical modeling could be an effective tool for measuring the detrimental global burden of pandemic infections. Additionally, they could be a really useful method for future pandemics and would assist the healthcare and public health systems with more accurate and valid information.

Characteristics of published/registered clinical trials on COVID-19 treatment: A systematic review.

OBJECTIVES: Due to the rapid spread of COVID-19 worldwide, many countries have designed clinical trials to find efficient treatments. We aimed to critically report the characteristics of all the registered and published randomized clinical trials (RCTs) conducted on COVID-19, and summarize the evaluation of potential therapies developed in various regions. EVIDENCE ACQUISITION: We comprehensively searched PubMed, Cochrane Library, Web of Science, Scopus, and Clinicaltrial.gov databases to retrieve all the relevant studies up to July 19, 2021, in conformity with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart. We included all English-language published/registered RCTs on COVID-19, and excluded non-RCT, in-vitro/in-vivo, editorials, and review studies. Two reviewers independently evaluated all the records, and then analyzed by using SPSS 17. RESULTS: Within 3018 included studies, 2801 (92.8%) and 217 (7.2%) were registered or published RCTs consisting of about 600 synthetic drugs. Herbal medicines have been studied in 23 trials (10.6%) among the published RCTs and in 357 registered RCTs (12.7%). Hydroxychloroquine 23 (10.6%) and convalescent plasma 194 (6.9%) alone or in combination with other agents were the most frequently used interventions in published and registered RCTs, respectively. Most published RCTs have been conducted in Western Pacific Region (WPRO) (50 trials, 23.0%) including 45 trials from China. Also, a greater proportion of registered RCTs have been conducted in the Region of the Americas (PAHO) (885 trials, 31.6%) including 596 RCTs from the United States (U.S). Globally, 283 registered trials have been conducted to assess new developed vaccines for COVID or previously established for other disorders. CONCLUSION: The present study highlighted the wide range of potential therapeutic agents in published and registered COVID-19 clinical trials across a wide range of regions. However, it is urgently required to global coordination in order to conduct more well-designed trials and progress in discovering safe and effective treatments.