The outbreak of coronavirus disease 2019 (COVID-19) is one of the main public health challenges currently facing the world. Because of its high transmissibility, COVID-19 has already caused extensive morbidity and mortality in many countries throughout the world. An accurate estimation of the basic reproduction number (R0) of COVID-19 would be beneficial for prevention programs. In light of discrepancies in original research on this issue, this systematic review and meta-analysis aimed to estimate the pooled R0 for COVID-19 in the current outbreak. International databases (including Google Scholar, Science Direct, PubMed, and Scopus) were searched to identify studies conducted regarding the R0 of COVID-19. Articles were searched using the following keywords: "COVID-19" and "basic reproduction number" or "R0." The heterogeneity among studies was assessed using the I2 index, the Cochran Q test, and T2. A random-effects model was used to estimate R0 in this study. The mean reported R0 in the identified articles was 3.38±1.40, with a range of 1.90 to 6.49. According to the results of the random-effects model, the pooled R0 for COVID-19 was estimated as 3.32 (95% confidence interval, 2.81 to 3.82). According to the results of the meta-regression analysis, the type of model used to estimate R0 did not have a significant effect on heterogeneity among studies (p=0.81). Considering the estimated R0 for COVID-19, reducing the number of contacts within the population is a necessary step to control the epidemic. The estimated overall R0 was higher than the World Health Organization estimate.

Background: The current study aimed to identify effective factors on the death among COVID-19 patients. Methods: All articles published in the period Jan 1, 2020, to Mar 23, 2020, written in English and reporting factors associated with COVID-19 mortality were reviewed. The random-effects model with 95% CI was used to calculate the pooled Odds Ratio (OR) and Hazard Ratio (HR). Data were analyzed using Stata ver.11.0. Results: The older age OR: 1.21(1.10-1.33) and male gender OR: 1.41(1.04-1.89) were most prone to death due to COVID-19. The Comorbidity with some chronic diseases such as Diabetes type2 OR: 2.42(1.06-5.52), Hypertension OR: 2.54(1.21-5.32), Kidney disorder OR: 2.61(1.22-5.60), Respiratory disorder 3.09 (1.39-6.88) and Heart diseases OR: 4.37 (1.13-16.90) can increase the risk of COVID19 mortality. Conclusion: Infection with COVID-19 is associated with substantial mortality mainly in older patients with comorbidities. We found the significant effect of age, gender and comorbidities such as Diabetes Mellitus, Hypertension, Kidney disorders and Heart diseases on the risk of death in patients with COVID-19. The factors associated with mortality found in this research can help to recognize patients with COVID-19 who are at higher risk of a poor prognosis. Monitoring these factors can serve to give early warning for the appropriate interventions.

Considering the design effect in cluster sampling

Background and Objective: Numerous actions have been taken to control the COVID-19 pandemic and reduce their morbidity and mortality. One of the most important measures in this regard is social distancing. However, there is limited evidence on the effectiveness of social distancing on COVID-19 incidence and mortality. Thus, the current study aimed to assess the effectiveness of social distancing measures on the COVID-19 incidence and mortality in Iran. Materials and Methods: In the current quasi-experimental study, we evaluated the daily incidence cases and the number of deaths of COVID-19 in Iran before and after the implementation of social distancing measures. The segmented regression model was used to analyze the data. We also performed the interrupted time series (ITS) analysis using Newey ordinary least squares (OLS) regression-based methods. Results: After the implementation of social distancing, the trend of both daily new cases and deaths due to COVID-19 was decreasing [(ß = − 1.70 (95% CI = [− 2.30 – − 1.10; P < 0.001])) and (ß = − 0.07 (95% CI = [− 0.10 − − 0.05; P < 0.001], respectively))]. Conclusion: Social distancing along with other public health interventions could reduce the morbidity and mortality of COVID-19 to some degrees, and it seems to be crucial to control the pandemic.

Anesthesiology and Pain Medicine

The purpose of this study was to compare the effectiveness of Atazanavir/Ritonavir/Dolutegravir/Hydroxychloroquine and Lopinavir/Ritonavir/Hydroxychloroquine treatment regimens in COVID‐19 patients based on clinical and laboratory parameters. We prospectively evaluated the clinical and laboratory outcomes of 62 moderate to severe COVID‐19 patients during a 10‐day treatment plan. Patients were randomly assigned to either KH (receiving Lopinavir/Ritonavir [Kaletra] plus Hydroxychloroquine) or ADH (receiving Atazanavir/Ritonavir, Dolutegravir, and Hydroxychloroquine) groups. During this period, clinical and laboratory parameters and outcomes such as intensive care unit (ICU) admission or mortality rate were recorded. Compared to the KH group, after the treatment period, patients in the ADH group had higher activated partial thromboplastin time (aPTT) (12, [95% confidence interval [CI]: 6.97, 17.06), p = <0.01), international normalized ratio (INR) (0.17, [95% CI: 0.07, 0.27), p = <0.01) and lower C‐reactive protein (CRP) (−14.29, (95% CI: −26.87, −1.71), p = 0.03) and potassium (−0.53, (95% CI: −1.03, −0.03), p = 0.04) values. Moreover, a higher number of patients in the KH group needed invasive ventilation (6 (20%) vs. 1 (3.1%), p = 0.05) and antibiotic administration (27 (90%) vs. 21(65.6), p = 0.02) during hospitalization while patients in the ADH group needed more corticosteroid administration (9 (28.1%) vs. 2 (6.7%), p = 0.03). There was no difference in mortality rate, ICU admission rate, and hospitalization period between the study groups. Our results suggest that the Atazanavir/Dolutegravir treatment regimen may result in a less severe disease course compared to the Lopinavir/Ritonavir treatment regimen and can be considered as an alternative treatment option beside standard care. However, to confirm our results, larger‐scale studies are recommended.