Institutional risk factors for norovirus outbreaks in Hong Kong elderly homes: a retrospective cohort study
2011

Risk Factors for Norovirus Outbreaks in Hong Kong Elderly Homes

Sample size: 748 publication 10 minutes Evidence: high

Author Information

Author(s): Lin Hualiang, Ng Sammy, Chan Shelley, Chan Wai Man, Lee Krystal CK, Ho Suzanne C, Tian Linwei

Primary Institution: Chinese University of Hong Kong

Hypothesis

What are the institutional risk factors that predispose elderly homes in Hong Kong to norovirus outbreaks?

Conclusion

Larger elderly home capacity, higher staff-to-resident ratios, and better wheelchair accessibility increase the risk of norovirus outbreaks, while partitions between beds reduce this risk.

Supporting Evidence

  • 276 norovirus outbreaks were confirmed during the study period.
  • The outbreak rate was 12.2 per 100 home-years.
  • Elderly homes with larger capacity had a rate ratio of 1.4 for outbreaks.
  • Higher staff-to-resident ratios were associated with a rate ratio of 1.2 for outbreaks.
  • Better wheelchair accessibility had a rate ratio of 2.0 for outbreaks.
  • Partitions between beds were linked to a lower outbreak rate with a rate ratio of 0.6.

Takeaway

Elderly homes with more residents and staff are more likely to have norovirus outbreaks, but having partitions between beds can help keep residents safe.

Methodology

A retrospective cohort study followed 748 elderly homes from January 2005 to December 2007, analyzing risk factors for norovirus outbreaks using Cox regression models.

Potential Biases

Potential selection bias due to exclusion of 'self-care hostels' and reliance on outbreak reporting.

Limitations

The study may have underreported outbreaks and excluded certain types of homes, which could introduce bias.

Participant Demographics

The study included elderly homes in Hong Kong, accommodating 57,321 elderly residents.

Statistical Information

P-Value

<0.0001

Confidence Interval

95% CI: 9.9-14.6

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1471-2458-11-297

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