Student or educator? Sign up with your school email and get 6 months of Pro free.
Cited by 175

The DOI matches its Crossref record; 3 of the 3 references it cites were found in a registry or an index.

Risk Factors for Severe Illness with 2009 Pandemic Influenza A (H1N1) Virus Infection in China

Open access
Yu, Hongjie, Feng, Zijian, Uyeki, Timothy M., Liao, Qiaohong, Zhou, Lei, Feng, Luzhao, Ye, Min, Xiang, Nijuan, Huai, Yang, Yuan, Yuan, Jiang, Hui, Zheng, Yingdong, Gargiullo, Paul, Peng, Zhibin, Feng, Yunxia, Zheng, Jiandong, Xu, Cuiling, Zhang, Yanping, Shu, Yuelong, Gao, Zhancheng, Yang, Weizhong, Wang, Yu·2011·Clinical Infectious Diseases

Abstract

BACKGROUND: Data on risk factors for severe outcomes from 2009 pandemic influenza A (H1N1) virus infection are limited outside of developed countries. METHODS: We reviewed medical charts to collect data from patients hospitalized with laboratory-confirmed 2009 H1N1 infection who were identified across China during the period from September 2009 through February 2010, and we analyzed potential risk factors associated with severe illness (defined as illness requiring intensive care unit admission or resulting in death). RESULTS: Among 9966 case patients, the prevalence of chronic medical conditions (33% vs 14%), pregnancy (15% vs 7%), or obesity (19% vs 14%) was significantly higher in those patients with severe illness than it was in those with less severe disease. In multivariable analyses, among nonpregnant case patients aged ≥ 2 years, having a chronic medical condition significantly increased the risk of severe outcome among all age groups, and obesity was a risk factor among those <60 years of age. The risk of severe illness among pregnant case patients was significantly higher for those in the second and third trimesters. The risk of severe illness was increased when oseltamivir treatment was initiated ≥ 5 days after illness onset (odds ratio, 1.42; 95% confidence interval, 1.20-1.67). For persons <60 years of age, the prevalence of obesity among case patients with severe illness was significantly greater than it was among those without severe illness or among the general population. CONCLUSIONS: Risk factors for severe 2009 H1N1 illness in China were similar to those observed in developed countries, but there was a lower prevalence of chronic medical conditions and a lower prevalence of obesity. Obesity was a risk factor among case patients < 60 years of age. Early initiation of oseltamivir treatment was most beneficial, and there was an increased risk of severe disease when treatment was started ≥ 5 days after illness onset.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1093/cid/ciq144

Cites

3 of 3 references verified0 citation errors · 0 not checkable

Statistics

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cites

Show all 3 references

Cited by

See all 175

Metadata

Authors
Yu, H., Feng, Z., Uyeki, T. M., Liao, Q., Zhou, L., Feng, L., Ye, M., Xiang, N., Huai, Y., Yuan, Y., Jiang, H., Zheng, Y., Gargiullo, P., Peng, Z., Feng, Y., Zheng, J., Xu, C., Zhang, Y., Shu, Y., Gao, Z., Yang, W., & Wang, Y.
Venue
Clinical Infectious Diseases
Published
2011-02-15
Volume
52
Issue
4
Pages
457-465
ISSN
  • 1058-4838 (ISSN-L)
  • 1537-6591
OpenAlex
W2124517342
Cited by
175
References
3
FWCI
14.70
Type
journal article
Language
en
Open access
bronze

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review

How to cite

Cite CoChat for the checks on this page, and the paper for its own findings.

This page
CoChat. (2026). Citation check: Risk Factors for Severe Illness with 2009 Pandemic Influenza A (H1N1) Virus Infection in China. https://app.cochat.ai/papers/10.1093/cid/ciq144
The paper
Yu, H., Feng, Z., Uyeki, T. M., Liao, Q., Zhou, L., Feng, L., Ye, M., Xiang, N., Huai, Y., Yuan, Y., Jiang, H., Zheng, Y., Gargiullo, P., Peng, Z., Feng, Y., Zheng, J., Xu, C., Zhang, Y., Shu, Y., . . . Wang, Y. (2011). Risk Factors for Severe Illness with 2009 Pandemic Influenza A (H1N1) Virus Infection in China. Clinical Infectious Diseases. https://doi.org/10.1093/cid/ciq144

Data sources

Bibliographic data: Semantic Scholar, OpenAlex, Crossref.

Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.