ArticleThe Lancet regional health. Europe2021
Mortality comparison between the first and second/third waves among 3,795 critical COVID-19 patients with pneumonia admitted to the ICU: A multicentre retrospective cohort study.
Article in The Lancet regional health. Europe, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 105 papers, 5 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
105 citing papers in PubMed, 5 syntheses or guidelines pooled it, 206 citations in OpenAlex.
- Prevalence and Risk Factors Associated With ICU Mortality in Ethiopia: A Systemic Review and Meta-Analysis.Nursing open · 2025Pooled it
- Efficacy and safety of human umbilical cord-derived mesenchymal stem cells for COVID-19 pneumonia: a meta-analysis of randomized controlled trials.Stem cell research & therapy · 2023Pooled it
- The impact of immunocompromise on outcomes of COVID-19 in children and young people-a systematic review and meta-analysis.Frontiers in immunology · 2023Pooled it
- Psychotropic drug repurposing for COVID-19: A Systematic Review and Meta-Analysis.European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology · 2023Pooled it
- Predicting COVID-19 prognosis in the ICU remained challenging: external validation in a multinational regional cohort.Journal of clinical epidemiology · 2022Pooled it
- Timing of intubation and ICU mortality in COVID-19 patients: a retrospective analysis of 4198 critically ill patients during the first and second waves.BMC anesthesiology · 2023Trial
- Critical care trends across five waves of COVID-19 in Pakistan: A multi-center observational study from the Pakistan Registry of Intensive CarE (PRICE).BMC infectious diseases · 2026Observational
- Comparative analysis of COVID-19 critically ill patients across four pandemic waves in Greece.Journal of critical care medicine (Universitatea de Medicina si Farmacie din Targu-Mures) · 2025Article
- The Prognostic Value of (1→3)-β-D-Glucan in COVID-19 Patients with and Without Secondary Fungal Disease.Journal of fungi (Basel, Switzerland) · 2025Article
- The COVIDTrach prospective cohort study on outcomes in 1982 tracheostomised COVID-19 patients during the first and second UK pandemic waves.Scientific reports · 2025Article
- Does Empirical Antibiotic Use Improve Outcomes in Ventilated Patients with Pandemic Viral Infection? A Multicentre Retrospective Study.Antibiotics (Basel, Switzerland) · 2025Article
- Corticosteroids and long-term pulmonary function after critical illness due to COVID-19- a single-center cohort study.BMC pulmonary medicine · 2025Observational
- Unraveling relevant cross-waves pattern drifts in patient-hospital risk factors among hospitalized COVID-19 patients using explainable machine learning methods.BMC infectious diseases · 2025Article
- A transfer triage tool for COVID-19 mass critical care surges.Scientific reports · 2025Observational
- Cost-effectiveness Analysis of Nirmatrelvir/Ritonavir for COVID-19 Among Individuals at High Risk: A Modeling Study.Open forum infectious diseases · 2025Article
- Early bacterial co-infections and ventilator-associated lower respiratory tract infections among intubated patients during the first and second COVID-19 waves: a European comparative cohort study.Respiratory research · 2025Article
- Article
- Does experience matter? Understanding the mechanism of the volume-outcome relationship: Learning-by-doing or economies of scale.PloS one · 2025Article
- Burden of acute and long-term COVID-19: a nationwide study in Bahrain.Frontiers in public health · 2025Observational
- Article
45 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
29 authors at 20 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundIt is unclear whether the changes in critical care throughout the pandemic have improved the outcomes in coronavirus disease 2019 (COVID-19) patients admitted to the intensive care units (ICUs).
methodsWe conducted a retrospective cohort study in adults with COVID-19 pneumonia admitted to 73 ICUs from Spain, Andorra and Ireland between February 2020 and March 2021. The first wave corresponded with the period from February 2020 to June 2020, whereas the second/third waves occurred from July 2020 to March 2021. The primary outcome was ICU mortality between study periods. Mortality predictors and differences in mortality between COVID-19 waves were identified using logistic regression.
findingsAs of March 2021, the participating ICUs had included 3795 COVID-19 pneumonia patients, 2479 (65·3%) and 1316 (34·7%) belonging to the first and second/third waves, respectively. Illness severity scores predicting mortality were lower in the second/third waves compared with the first wave according with the Acute Physiology and Chronic Health Evaluation system (median APACHE II score 12 [IQR 9-16] vs 14 [IQR 10-19]) and the organ failure assessment score (median SOFA 4 [3-6] vs 5 [3-7],
interpretationDespite substantial changes on supportive care and management, we did not find significant improvement on case-fatality rates among critical COVID-19 pneumonia patients.
fundingRicardo Barri Casanovas Foundation (RBCF2020) and SEMICYUC.
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.