Association between household size and COVID-19: A UK Biobank observational study

• Published in: Journal of the Royal Society of Medicine 2022-04, Vol.115 (4), p.138-144
• Main Authors: Gillies, Clare L, Rowlands, Alex V, Razieh, Cameron, Nafilyan, Vahé, Chudasama, Yogini, Islam, Nazrul, Zaccardi, Francesco, Ayoubkhani, Daniel, Lawson, Claire, Davies, Melanie J, Yates, Tom, Khunti, Kamlesh
• Format: Article
• Language: English
• Subjects: Biological Specimen Banks; COVID-19 - epidemiology; Hospitalization; Humans; SARS-CoV-2; United Kingdom - epidemiology
• ISSN: 0141-0768; 1758-1095; 1758-1095
• DOI: 10.1177/01410768211073923

Summary Objective To assess the association between household size and risk of non-severe or severe COVID-19. Design A longitudinal observational study. Setting This study utilised UK Biobank linked to national SARS-CoV-2 laboratory test data. Participants 401,910 individuals with available data on household size in UK Biobank. Main outcome measures Household size was categorised as single occupancy, two-person households and households of three or more. Severe COVID-19 was defined as a positive SARS-CoV-2 test on hospital admission or death with COVID-19 recorded as the underlying cause; and non-severe COVID-19 as a positive test from a community setting. Logistic regression models were fitted to assess associations, adjusting for potential confounders. Results Of 401,910 individuals, 3612 (1%) were identified as having suffered from a severe COVID-19 infection and 11,264 (2.8%) from a non-severe infection, between 16 March 2020 and 16 March 2021. Overall, the odds of severe COVID-19 was significantly higher among individuals living alone (adjusted odds ratio: 1.24 [95% confidence interval: 1.14 to 1.36], or living in a household of three or more individuals (adjusted odds ratio: 1.28 [1.17 to 1.39], when compared to individuals living in a household of two. For non-severe COVID-19 infection, individuals living in a single-occupancy household had lower odds compared to those living in a household of two (adjusted odds ratio: 0.88 [0.82 to 0.93]. Conclusions Odds of severe or non-severe COVID-19 infection were associated with household size. Increasing understanding of why certain households are more at risk is important for limiting spread of the infection.