Sharing a household with children and risk of COVID-19: a study of over 300 000 adults living in healthcare worker households in Scotland

  1. Rachael Wood
  2. Emma Thomson
  3. Robert Galbraith
  4. Ciara Gribben
  5. David Caldwell
  6. Jennifer Bishop
  7. Martin Reid
  8. Anoop S V Shah
  9. Kate Templeton
  10. David Goldberg
  11. Chris Robertson
  12. Sharon J Hutchinson
  13. Helen M Colhoun
  14. Paul M McKeigue
  15. David A McAllister

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Abstract

Children are relatively protected from COVID-19, due to a range of potential mechanisms. We investigated if contact with children also affords adults a degree of protection from COVID-19.

Design

Cohort study based on linked administrative data.

Setting

Scotland.

Study population

All National Health Service Scotland healthcare workers and their household contacts as of March 2020.

Main exposure

Number of young children (0–11 years) living in the participant’s household.

Main outcomes

COVID-19 requiring hospitalisation, and any COVID-19 (any positive test for SARS-CoV-2) in adults aged ≥18 years between 1 March and 12 October 2020.

Results

241 266, 41 198, 23 783 and 3850 adults shared a household with 0, 1, 2 and 3 or more young children, respectively. Over the study period, the risk of COVID-19 requiring hospitalisation was reduced progressively with increasing numbers of household children—fully adjusted HR (aHR) 0.93 per child (95% CI 0.79 to 1.10). The risk of any COVID-19 was similarly reduced, with the association being statistically significant (aHR per child 0.93; 95% CI 0.88 to 0.98). After schools reopened to all children in August 2020, no association was seen between exposure to young children and risk of any COVID-19 (aHR per child 1.03; 95% CI 0.92 to 1.14).

Conclusion

Between March and October 2020, living with young children was associated with an attenuated risk of any COVID-19 and COVID-19 requiring hospitalisation among adults living in healthcare worker households. There was no evidence that living with young children increased adults’ risk of COVID-19, including during the period after schools reopened.

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  1. Version published to 10.1136/archdischild-2021-321604
  2. ScreenIT

    SciScore for 10.1101/2020.09.21.20196428: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    No key resources detected.

    Results from OddPub: Thank you for sharing your code.

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    This study has some limitations. The observed inverse association between living with young children and adults’ risk of COVID-19 was not strong, and could be a chance finding. Our primary outcome, COVID-19 requiring hospitalisation, was uncommon; hence HR confidence intervals were wide. Although we suspected that statistical power would be limited, we pre-specified this as the primary outcome as we were concerned that high rates of (non-SARS-CoV-2) acute respiratory infection in households with small children might have led to higher levels of testing for SARS-CoV-2 and hence biased ascertainment of any COVID-19. The level of testing was indeed higher among those adults who shared a household with young children. However, point estimates for COVID-19 requiring hospitalisation and any COVID-19 were similar, and for the latter they were statistically significant. Another possibility is that, despite extensive adjustment for potential confounders, the observed inverse association may be the result of residual confounding. On stratified analyses, the inverse association was evident for adults living in part time healthcare worker households, but less obvious for those living in full time healthcare worker households. Since part-time workers with increasing numbers of children likely work fewer hours (and therefore have lower occupational exposure to SARS-CoV-2), and since we lacked accurate data on hours worked during the pandemic, we cannot exclude the possibility of unmeasured...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

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  3. Version published to 10.1101/2020.09.21.20196428v2 on medRxiv
  4. Version published to 10.1101/2020.09.21.20196428v1 on medRxiv