Clinical outcomes and characteristics of critically ill patients with influenza- and COVID-19-induced ARDS: A retrospective, matched cohort study

Comparative Evaluation of Risk of Death in Mechanically Ventilated Patients With COVID-19 and Influenza: A Population-Based Cohort Study

Background

Reports on the comparative mortality among mechanically ventilated patients with coronavirus disease 2019 (COVID-19) and influenza show conflicting findings, but studies focused largely on the early phase of the pandemic, using historical influenza comparators. We sought to examine the population-level comparative mortality among mechanically ventilated patients with COVID-19 during the latter pandemic years using contemporaneous influenza comparators.

Methods

We used a statewide dataset to identify mechanically ventilated hospitalizations aged ≥ 18 years with COVID-19 or influenza in Texas between October 2021 and March 2023. Their comparative short-term mortality (in-hospital death or discharge to hospice) was estimated using overlap propensity score weighting (primary model), entropy balance, and hierarchical logistic models.

Results

Among 22,195 mechanically ventilated hospitalizations, 19,659 (88.6%) had COVID-19 and 2,536 (11.4%) had influenza. Compared to mechanically ventilated hospitalizations with influenza, those with COVID-19 were more commonly racial or ethnic minority (49.3% vs. 48.4%) and had lower mean (standard deviation (SD)) Deyo comorbidity index (2.04 (2.03) vs. 2.53 (1.91)), but higher number of organ dysfunctions (2.60 (1.37) vs. 2.13 (1.27)), respectively. Short-term mortality among mechanically ventilated hospitalizations with COVID-19 and influenza was 49.1% vs. 20.7%. The risk of short-term mortality was attenuated but remained higher among hospitalizations with COVID-19 in the primary model (adjusted risk ratio: 1.24 (95% confidence interval (CI): 1.18 - 1.30); adjusted risk difference 8.8% (95% CI: 6.7 - 10.4)), with consistent findings in alternative models, subgroups, and sensitivity analyses.

Conclusions

Population-level short-term mortality among mechanically ventilated hospitalizations with COVID-19 has been higher than that among those with influenza during the latter years of the pandemic.

Differences in clinical characteristics between coronavirus disease 2019 (COVID-19) and influenza: a systematic review and meta-analysis

The coronavirus disease 2019 (COVID-19) epidemic has brought major challenges to the global health system, and influenza is also a problem that cannot be ignored. We aimed to explore and compare the clinical characteristics of COVID-19 and influenza to deepen the understanding of these two diseases and provide some guidance for clinicians to make differential diagnoses. We searched PubMed, Embase and Web of Science for articles and performed a meta-analysis using Stata 14.0 with a random-effects model. This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. One hundred articles involving 226,913 COVID-19 patients and 201,617 influenza patients were included, and all the articles included patients with these two diseases as experimental and control groups. Compared to influenza, COVID-19 was more common among men (OR = 1.46, 95% CI: 1.23-1.74) and people with a higher body mass index (MD = 1.43, 95% CI: 1.09-1.77). The proportion of current smokers among COVID-19 patients was lower than that among influenza patients (OR = 0.25, 95% CI: 0.18-0.33). Patients with COVID-19 had longer stays in the hospital (MD = 3.20, 95% CI: 2.58-3.82) and ICU (MD = 3.10, 95% CI: 1.44-4.76), required mechanical ventilation more frequently (OR = 2.30, 95% CI: 1.77-3.00), and had higher mortality (OR = 2.22, 95% CI: 1.93-2.55). We also found significant differences in some blood parameters between the two groups of patients. Upper respiratory symptoms were more obvious in influenza patients, and the proportion of comorbidities was higher than that among COVID-19 patients. There are some differences in the major characteristics, symptoms, laboratory findings and comorbidities between COVID-19 patients and influenza patients. COVID-19 patients often require more medical resources and have worse clinical outcomes.

Association between COVID-19 infection and new-onset dementia in older adults: a systematic review and meta-analysis

BACKGROUND

The relationship between COVID-19 infection and a possible increased likelihood of older adults developing new-onset dementia (NOD) remains elusive.

METHODS

A thorough search was performed across several databases including MEDLINE/PubMed, PsycINFO, Scopus, medRxiv, and PQDT Global for studies published in English from January 2020 to December 2023. Only original investigations exploring the link between COVID-19 infection and NOD were selected for inclusion. We assessed the risk of developing NOD, using Risk Ratio (RR) for measurement. Control groups were categorized as: (i) a non-COVID cohort with other respiratory infections [control group (C1)]; and (ii) a non-COVID cohort with otherwise unspecified health status [control group (C2)]. Follow-up periods were divided into intervals of 3, 6, 12, and 24 months post-COVID.

RESULTS

11 studies (involving 939,824 post-COVID-19 survivors and 6,765,117 controls) were included in the review. Across a median observation period of 12 months post-COVID, the overall incidence of NOD was about 1.82% in the COVID-infected group, compared to 0.35% in the non-COVID-infected group. The overall pooled meta-analysis showed a significantly increased NOD risk among COVID-19 older adult survivors compared to non-COVID-19 controls (RR = 1.58, 95% CI 1.21-2.08). Similar increased NOD risks were observed in subgroup analyses restricted to an observational period of 12 months (RR = 1.56, 95% CI 1.21-2.01), as well as in five studies that employed propensity score matching to sufficiently and effectively control for multiple confounding covariates (RR = 1.46, 95% CI 1.10-1.94). COVID-19 group and C1 group shared a comparably increased risk of developing NOD (overall RR = 1.13, 95% CI 0.92-1.38).

DISCUSSION

Under normal circumstances, we believe that COVID-19 infection is likely to be a risk factor for developing NOD in older adults over time. While the increased NOD risk due to COVID-19 infection appears to be similar to that associated with other respiratory infections, it warrants and necessitates investigation with longer observations.

Comparison of Clinical Characteristics and Outcomes in Intensive Care Units Between Patients with Coronavirus Disease 2019 (COVID-19) and Patients with Influenza: A Systematic Review and Meta-Analysis

BACKGROUND

Severe infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or influenza virus can cause patients to be admitted to intensive care units (ICUs). It is necessary to understand the differences in clinical characteristics and outcomes between these two types of critically ill patients.

METHODS

We searched Embase, PubMed, and Web of Science for articles and performed a meta-analysis using Stata 14.0 with a random-effects model. This paper was written in strict accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Thirty-five articles involving 131,692 ICU patients with coronavirus disease 2019 (COVID-19) and 30,286 ICU patients with influenza were included in our meta-analysis. Compared with influenza patients, COVID-19 patients were more likely to be male (odds ratio (OR) = 1.75, 95% CI: 1.54-1.99) and older (standardized mean difference (SMD) = 0.16, 95% CI: 0.03-0.29). In terms of laboratory test results, COVID-19 patients had higher lymphocyte (SMD = 0.38, 95% CI: 0.17-0.59) and platelet counts (SMD = 0.52, 95% CI: 0.29-0.75) but lower creatinine (SMD = -0.29, 95% CI: -0.55-0.03) and procalcitonin levels (SMD = -0.78, 95% CI: -1.11-0.46). Diabetes (SMD = 1.27, 95% CI: 1.08-1.48) and hypertension (SMD = 1.30, 95% CI: 1.05-1.60) were more prevalent in COVID-19 patients, while influenza patients were more likely to have cancer (OR = 0.52, 95% CI: 0.44-0.62), cirrhosis (OR = 0.52, 95% CI: 0.44-0.62), immunodepression (OR = 0.38, 95% CI: 0.25-0.58), and chronic pulmonary diseases (OR = 0.35, 95% CI: 0.24-0.52). We also found that patients with COVID-19 had longer ICU stays (SMD = 0.20, 95% CI: 0.05-0.34), were more likely to develop acute respiratory distress syndrome (OR = 4.90, 95% CI: 2.77-8.64), and had higher mortality (OR = 1.35, 95% CI: 1.17-1.55).

CONCLUSIONS

There are some differences in the basic characteristics, comorbidities, laboratory test results and complications between ICU patients with COVID-19 and ICU patients with influenza. Critically ill patients with COVID-19 often require more medical resources and have worse clinical outcomes. PROSPERO Registration Number: CRD42023452238.