Kashour, Tarek

Abstract The rapid spread of severe acute respiratory syndrome coronavirus 2 infection across the globe triggered an unprecedented increase in research activities that resulted in an astronomical publication output of observational studies. However, most studies failed to apply fully the necessary methodological techniques that systematically deal with different biases and confounding, which not only limits their scientific merit but may result in harm through misleading information. In this article, we address a few important biases that can seriously threaten the validity of observational studies of coronavirus disease 2019 (COVID-19). We focus on treatment selection bias due to patients’ preference on goals of care, medical futility and disability bias, survivor bias, competing risks, and the misuse of propensity score analysis. We attempt to raise awareness and to help readers assess shortcomings of observational studies of interventions in COVID-19.

Abstract Background Statins up-regulate angiotensin-converting enzyme 2, the receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), while also exhibiting pleiotropic antiviral, antithrombotic, and anti-inflammatory properties. Uncertainties exist about their effect on the course of SARS-CoV-2 infection. We sought to systematically review the literature and perform a meta-analysis to examine the association between prior statin use and outcomes of patients with coronavirus disease 2019 (COVID-19). Methods We searched Ovid Medline, Web of Science, Scopus, and the preprint server medRxiv from inception to December 2020. We assessed the quality of eligible studies with the Newcastle-Ottawa quality scale. We pooled adjusted relative risk (aRRs) of the association between prior statin use and outcomes of patients with COVID-19 using the DerSimonian-Laird random-effects model and assessed heterogeneity using the I2 index. Results Overall, 19 (16 cohorts and 3 case-control) studies were eligible, with a total of 395 513 patients. Sixteen of 19 studies had low or moderate risk of bias. Among 109 080 patients enrolled in 13 separate studies, prior statin use was associated with a lower risk of mortality (pooled aRR, 0.65 [95% confidence interval {CI}, .56–.77], I2 = 84.1%) and a reduced risk of severe COVID-19 was also observed in 48 110 patients enrolled in 9 studies (pooled aRR, 0.73 [95% CI, .57–.94], I2 = 82.8%), with no evidence of publication bias. Conclusions Cumulative evidence suggests that prior statin use is associated with lower risks of mortality or severe disease in patients with COVID-19. These data support the continued use of statins medications in patients with an indication for lipid-lowering therapy during the COVID-19 pandemic.

AbstractMany meta‐analyses have been published about the efficacy of hydroxychloroquine (HCQ) in coronavirus disease 2019 (COVID‐19). Most of them included observational studies, and few have assessed HCQ as a prophylaxis or evaluated its safety profile. We searched multiple databases and preprint servers for randomized controlled trials (RCTs) that assessed HCQ for the treatment or prevention of COVID‐19. We summarized the effect of HCQ on mortality, viral clearance, and other clinical outcomes. Out of 768 papers screened, 21 RCTs with a total of 14,138 patients were included. A total of 9 inpatient and 3 outpatient RCTs assessed mortality in 8596 patients with a pooled risk difference of 0.01 (95% confidence interval [CI] 0.00–0.03, I2 = 1%, p = 0.07). Six studies assessed viral clearance at 7 days with a pooled risk ratio (RR) of 1.11 (95% CI 0.86–1.42, I2 = 61%, p = 0.44) and 5 studies at 14 days with a pooled RR of 0.96 (95% CI 0.89–1.04, I2 = 0%, p = 0.34). Several trials showed no significant effect of HCQ on other clinical outcomes and. Five prevention RCTs with 5012 patients found no effect of HCQ on the risk of acquiring COVID‐19. Thirteen trials showed that HCQ was associated with increased risk of adverse events. We observed, with high level of certainty of evidence, that HCQ is not effective in reducing mortality in patients with COVID‐19. Lower certainty evidence also suggests that HCQ neither improves viral clearance and other clinical outcomes, nor prevents COVID‐19 infection in patients with high‐risk exposure. HCQ is associated with an increased rate of adverse events.

Background: Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are known to increase the expression of angiotensin converting enzyme 2 receptor, which has been shown to be the receptor for the acute severe respiratory syndrome coronavirus 2 (SARS-CoV-2). Areas of Uncertainty: Based on these observations, speculations raised the concerns that ACEIs/ARBs users would be more susceptible to SARS-CoV-2 infection and would be at higher risk for severe COVID-19 disease and death. Therefore, we systematically reviewed the literature and performed a meta-analysis of the association between prior use of ACEIs and ARBs and mortality due to COVID-19 disease. Data Sources: A comprehensive search of several databases from November 2019 to June 18, 2020 was conducted. The databases included Ovid MEDLINE(R) and Epub Ahead of Print, In-Process and Other Non-Indexed Citations and Daily, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, Web of Science, and Scopus. Medrxiv.org was also searched for unpublished data. Therapeutic Advances: Nine studies with a total of 18,833 patients infected with SARS-CoV-2 met our eligibility criteria. Prior use of ACEIs and/or ARBs was associated with reduced mortality among SARS-CoV-2-infected patients, with a pooled adjusted relative risk (aRR) from 6 studies of 0.63, 95% confidence interval (CI) (0.42–0.94) (I 2 = 65%). Three studies reported separately on ACEIs or ARBs and their association with survival among SARS-CoV-2-infected patients, with a pooled adjusted relative risk of 0.78, 95% CI (0.58–1.04) (I 2 = 0%) and 0.97, 95% CI (0.73–1.30) (I 2 = 0%) respectively. The results of sensitivity analyses were consistent with the main analysis. Conclusion: Our meta-analysis suggests that use of ACEIs/ARBs is associated with a decreased risk of death among SARS-CoV-2-infected patients. This finding provides a reassurance to the public not to stop prescribed ACEIs/ARBs because of fear of severe COVID-19.

Abstract Objectives Clinical studies of chloroquine (CQ) and hydroxychloroquine (HCQ) in COVID-19 disease reported conflicting results. We sought to systematically evaluate the effect of CQ and HCQ with or without azithromycin on outcomes of COVID-19 patients. Methods We searched multiple databases, preprints and grey literature up to 17 July 2020. We pooled only adjusted-effect estimates of mortality using a random-effect model. We summarized the effect of CQ or HCQ on viral clearance, ICU admission/mechanical ventilation and hospitalization. Results Seven randomized clinical trials (RCTs) and 14 cohort studies were included (20 979 patients). Thirteen studies (1 RCT and 12 cohort studies) with 15 938 hospitalized patients examined the effect of HCQ on short-term mortality. The pooled adjusted OR was 1.05 (95% CI 0.96–1.15, I2 = 0%). Six cohort studies examined the effect of the HCQ+azithromycin combination with a pooled adjusted OR of 1.32 (95% CI 1.00–1.75, I2 = 68.1%). Two cohort studies and four RCTs found no effect of HCQ on viral clearance. One small RCT demonstrated improved viral clearance with CQ and HCQ. Three cohort studies found that HCQ had no significant effect on mechanical ventilation/ICU admission. Two RCTs found no effect for HCQ on hospitalization risk in outpatients with COVID-19. Conclusions Moderate certainty evidence suggests that HCQ, with or without azithromycin, lacks efficacy in reducing short-term mortality in patients hospitalized with COVID-19 or risk of hospitalization in outpatients with COVID-19.