ArticleEmerging microbes & infections2023
Changes in the characteristics and outcomes of COVID-19 patients from the early pandemic to the delta variant epidemic: a nationwide population-based study.
Article in Emerging microbes & infections, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 27 papers, 2 of them syntheses that pooled it.
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Who cites it
27 citing papers in PubMed, 2 syntheses or guidelines pooled it, 49 citations in OpenAlex.
- Trends in symptom prevalence and sequential onset of SARS-CoV-2 infection from 2020 to 2022 in East and Southeast Asia: a trajectory pattern exploration based on summary data.Archives of public health = Archives belges de sante publique · 2024Pooled it
- Antidiabetic agent use and clinical outcomes in patients with diabetes hospitalized for COVID-19: a systematic review and meta-analysis.Frontiers in endocrinology · 2024Pooled it
- One-Year Survival and Changes in Care Needs Among Hospitalized Older Patients With Coronavirus Disease 2019 in Japan: A Nara Kokuho Database Analysis.Geriatrics & gerontology international · 2026Article
- Article
- Comparison between the characteristics and outcomes of patients hospitalized for COVID-19 in three waves of the pandemic: a retrospective analysis.Infectious diseases of poverty · 2025Article
- Outcomes of COVID-19 in the Omicron-predominant wave: large-scale real-world data analysis with a comparison to influenza.Pneumonia (Nathan Qld.) · 2025Article
- Racial and ethnic differences in COVID-19 infection and vaccine uptake across multiple waves of the pandemic in Southeast Michigan: a retrospective cohort study.Frontiers in public health · 2025Article
- Risk factors for severe COVID-19 outcomes in the Asia-Pacific region: a literature review.Frontiers in public health · 2025Review
- Impact of COVID-19 vaccination status on hospitalization and disease severity: A descriptive study in Nagasaki Prefecture, Japan.Human vaccines & immunotherapeutics · 2024Article
- Clinical Course and Factors Correlated with Severe Morbidity and Mortality in Patients with Coronavirus Disease 2019 Undergoing Maintenance Dialysis in Kanagawa, Japan.Internal medicine (Tokyo, Japan) · 2024Observational
- Clinical Characteristics and Outcomes of Hospitalized COVID-19 Patients with Different Variants of SARS-CoV-2 in a Tertiary Care Hospital, Thailand.Tropical medicine and infectious disease · 2024Article
- Current status and clinical outcomes of pharmacotherapies according to SARS-CoV-2 mutations in patients with mild-to-moderate COVID-19: a retrospective single center study.BMC infectious diseases · 2024Article
- The immunoreactive signature of monocyte-derived dendritic cells from patients with Down syndrome.Clinical and experimental immunology · 2024Article
- Prognostic value of interleukin-6 serum levels in hospitalized COVID-19 patients: A case-control study in Iran.Health science reports · 2024Article
- Mortality and COVID Infection: Predictors of Mortality 10 Months after Discharge.Diseases (Basel, Switzerland) · 2024Article
- Managing and treating COVID-19 in patients with hematological malignancies: a narrative review and expert insights.Clinical and experimental medicine · 2024Review
- Clinical and epidemiological risk factors associated with hospitalization and mortality rate of COVID-19 patients in Banja Luka County: A retrospective observational cohort study on 40,000 patients.Journal of family medicine and primary care · 2024Article
- Gastrointestinal symptoms in COVID-19 and disease severity: a Japanese registry-based retrospective cohort study.Journal of gastroenterology · 2024Article
- Impact of preexisting interstitial lung disease on mortality in COVID-19 patients from the early pandemic to the delta variant epidemic: a nationwide population-based study.Respiratory research · 2024Article
- Article
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Authors and funding
13 authors at 1 institution in 1 country.
Funding
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has dramatically changed because of virus mutations, vaccine dissemination, treatment development and policies, among other factors. These factors have a dynamic and complex effect on the characteristics and outcomes of patients. Therefore, there is an urgent need to understand those changes and update the evidence. We used a large-scale real-world data set of 937,758 patients with COVID-19 from a nationwide claims database that included outpatients and inpatients in Japan to investigate the changes in their characteristics, outcomes and risk factors for severity/mortality from the early pandemic to the delta variant-predominant waves. The severity of COVID-19 was defined according to the modified World Health Organization clinical-progression ordinal scale. With changing waves, mean patient age decreased, and proportion of patients with comorbidities decreased. The incidences of "severe COVID-19 or death (i.e. ≥severe COVID-19)" and "death" markedly declined (5.0% and 2.9%, wild-type-predominant; 4.6% and 2.2%, alpha variant-predominant and 1.4% and 0.4%, delta variant-predominant waves, respectively). Across the wave shift, risk factors for ≥ severe COVID-19 and death, including older age, male, malignancy, congestive heart failure and chronic obstructive pulmonary disease, were largely consistent. The significance of some factors, such as liver disease, varied as per the wave. This study, one of the largest population-based studies on COVID-19, showed that patient characteristics and outcomes changed during the waves. Risk factors for severity/mortality were similar across all waves, but some factors were inconsistent. These data suggest that the clinical status of COVID-19 will change further with the coming epidemic wave.
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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.