Article Text

Original research
Compress the curve: a cross-sectional study of variations in COVID-19 infections across California nursing homes
  1. Ram Gopal1,
  2. Xu Han2,
  3. Niam Yaraghi3,4
  1. 1Warwick Business School, University of Warwick, Coventry, UK
  2. 2Gabelli School of Business, Fordham University, New York, New York, USA
  3. 3Miami Herbert Business School, University of Miami, Coral Gables, Florida, USA
  4. 4Governance Studies, The Brookings Institution, Washington, DC, USA
  1. Correspondence to Dr Niam Yaraghi; niamyaraghi{at}


Objective Nursing homes’ residents and staff constitute the largest proportion of the fatalities associated with COVID-19 epidemic. Although there is a significant variation in COVID-19 outbreaks among the US nursing homes, we still do not know why such outbreaks are larger and more likely in some nursing homes than others. This research aims to understand why some nursing homes are more susceptible to larger COVID-19 outbreaks.

Design Observational study of all nursing homes in the state of California until 1 May 2020.

Setting The state of California.

Participants 713 long-term care facilities in the state of California that participate in public reporting of COVID-19 infections as of 1 May 2020 and their infections data could be matched with data on ratings and governance features of nursing homes provided by Centers for Medicare & Medicaid Services (CMS).

Main outcome measure The number of reported COVID-19 infections among staff and residents.

Results Study sample included 713 nursing homes. The size of outbreaks among residents in for-profit nursing homes is 12.7 times larger than their non-profit counterparts (log count=2.54; 95% CI, 1.97 to 3.11; p<0.001). Higher ratings in CMS-reported health inspections are associated with lower number of infections among both staff (log count=−0.19; 95% CI, −0.37 to −0.01; p=0.05) and residents (log count=−0.20; 95% CI, −0.27 to −0.14; p<0.001). Nursing homes with higher discrepancy between their CMS-reported and self-reported ratings have higher number of infections among their staff (log count=0.41; 95% CI, 0.31 to 0.51; p<0.001) and residents (log count=0.13; 95% CI, 0.08 to 0.18; p<0.001).

Conclusions The size of COVID-19 outbreaks in nursing homes is associated with their ratings and governance features. To prepare for the possible next waves of COVID-19 epidemic, policy makers should use these insights to identify the nursing homes who are more likely to experience large outbreaks.

  • COVID-19
  • geriatric medicine
  • health policy

Data availability statement

All data and software code used in this research are made publicly available by the authors and their sources have been cited in the manuscript.

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:

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Data availability statement

All data and software code used in this research are made publicly available by the authors and their sources have been cited in the manuscript.

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  • RG, XH and NY contributed equally.

  • Correction notice This article has been corrected since it first published. The provenance and peer review statement has been included.

  • Contributors RG and NY designed the study. RG, XH and NY had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analyses. RG, XH and NY analysed the data. RG and NY interpreted the data. NY drafted the manuscript. NY and RG critically revised the manuscript.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

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  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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