key: cord-0996977-96pmvvmk
authors: Nafilyan, V.; Islam, N.; Ayoubkhani, D.; Gilles, C.; Katikireddi, S. V.; Mathur, R.; Tingay, K.; Asaria, M.; John, A.; Goldblatt, P.; Banerjee, A.; Glickman, M.; Khunti, K.
title: Ethnicity, Household Composition and COVID-19 Mortality: A National Linked Data Study
date: 2020-12-02
journal: nan
DOI: 10.1101/2020.11.27.20238147
sha: 67d58a7844a7a40c82617c7644fe8e689048f911
doc_id: 996977
cord_uid: 96pmvvmk

Background: Ethnic minorities have experienced disproportionate COVID-19 mortality rates. We estimated associations between household composition and COVID-19 mortality in older adults ([≥]65 years) using a newly linked census-based dataset, and investigated whether living in a multi-generational household explained some of the elevated COVID-19 mortality amongst ethnic minority groups. Methods: Using retrospective data from the 2011 Census linked to Hospital Episode Statistics (2017-2019) and death registration data (up to 27th July 2020), we followed adults aged 65 years or over living in private households in England from 2 March 2020 until 27 July 2020 (n=10,078,568). We estimated hazard ratios (HRs) for COVID-19 death for people living in a multi-generational household compared with people living with another older adult, adjusting for geographical factors, socio-economic characteristics and pre-pandemic health. We conducted a causal mediation analysis to estimate the proportion of ethnic inequalities explained by living in a multi-generational household. Results: Living in a multi-generational household was associated with an increased risk of COVID-19 death. After adjusting for confounding factors, the HRs for living in a multi-generational household with dependent children were 1.13 [95% confidence interval 1.01-1.27] and 1.17 [1.01-1.35] for older males and females. The HRs for living in a multi-generational household without dependent children were 1.03 [0.97 - 1.09] for older males and 1.22 [1.12 - 1.32] for older females. Living in a multi-generational household explained between 10% and 15% of the elevated risk of COVID-19 death among older females from South Asian background, but very little for South Asian males or people in other ethnic minority groups. Conclusion: Older adults living with younger people are at increased risk of COVID-19 mortality, and this is a notable contributing factor to the excess risk experienced by older South Asian females compared to White females. Relevant public health interventions should be directed at communities where such multi-generational households are highly prevalent. Funding: This research was funded by the Office for National Statistics.

People of ethnic minority background in the UK and the USA have been disproportionately affected by the Coronavirus disease 2019 [1, 2, 3, 4, 5] compared to the White population, particularly Black and South Asian groups. Whilst several studies have investigated whether adjusting for socio-demographic and economic factors and medical history reduces the estimated difference in risk of mortality and hospitalisation [6, 7, 8] , the reasons for the differences in the risk of experiencing harms from COVID-19 are still being explored.

One important driver of these ethnic inequalities may be differences in household structure between ethnic groups. Household composition varies substantially between ethnic groups, with some ethnic minority populations more likely to live in large, multi-generational households [9] . While living in multi-generational households is associated with increased social capital [10] , which could have beneficial health effects [11] , it may also increase the risk of potential viral transmission [12, 13] . For older people, who are at greater risk of experiencing severe complications if infected, residing with younger people may represent an increase in exposure to infection, which could lead to an increased risk of hospitalisation and mortality from COVID-19. To the best of our knowledge, no study has yet examined whether the difference in household composition partly explains the elevated risk of COVID-19 mortality in ethnic minority groups.

In this study, we examined the relationship between household composition and COVID-19 mortality risk amongst older adults (≥65 years) in England, with a focus on multi-generational households (older adults living with younger adults or dependent children). We then investigated how the propensity to live in a multi-generation household varies across ethnic groups, and whether this heterogeneity contributes to the raised risk of COVID-19 mortality amongst ethnic minority groups compared to the White population.

This retrospective cohort study was based on the 2011 Census of England linked to mortality registration data and Hospital Episodes Statistics (2017 -2019). The study population included all usual residents of England aged 65 years or over in 2020, who had been enumerated in private households at the time of the 2011 Census (27 March 2011), had not moved to a care home by 2019 (identified by linking to the NHS Patient Register) and were still alive on 2 March 2020. We further excluded individuals who entered the UK in the year before Census due to their higher propensity to leave the UK prior to the study period, and those aged over 100 years at the time of the Census. Our study population consisted of 10,078,568 individuals aged 65 years or over at 2 March 2020 (See Supplementary Table 1 details on the number of participants at each stage of the sample selection).

To adjust for out-migration, we applied weights reflecting the probability of having remained in the country until March 2020 after being enumerated in March 2011, based on data from the NHS Patient Register and the International Passenger Survey (IPS). Further information on the data has already been published [6] . All the variables used in the analysis, including their definitions and sources, are detailed in Table 1. (COVID-19, virus identified) or U07.2 (COVID-19, virus not identified). We analysed deaths that occurred between 2 March 2020 and 28 July 2020, registered by 24 August 2020, which corresponds to the deaths that occurred during the first COVID-19 wave.

Household composition in 2020 was derived based the household composition at the time of the Census. We excluded people who died between 27 March 2011 and 1 March 2020 or had moved to a care home by 2019. To mitigate measurement error, we removed people aged 10 to 24 at the time of the Census because they are more likely to have moved out in 2020. We defined a multigenerational household to be a household in which someone aged 65 years or over on 2 March in 2020 co-resided with at least one other adult aged more than 20 years younger, or with at least one child. Our household composition variable classified households in five categories: Single; Two older adults; Multi-generational household without dependent children; Multi-generational household with dependent children; three or more older adults. As sensitivity analyses, we removed people aged 10 to 19 instead of 10 to 24).We also defined a multi-generational household to be one in which someone aged 65 years or over in 2020 co-resided with at least one other adult aged more than 15 years (instead of 20 years) younger.

In the mediation analysis, the exposure was self-reported ethnic affiliation based on a nine-group classification (see Table 1 ). The two mediators were binary variables for living in a multi-generational household with or without children.

Demographic factors, geographical variables, socio-economic characteristics and measures of prepandemic health are listed in Table 1 . These covariates were generally considered to be confounders of the relationship between household composition and COVID-19 mortality risk, and mediators of the ethnicity-mortality relationship (See Figure 1 ). Note: Household deprivation is defined according to four dimensions: employment (at least one household member is unemployed or long-term sick, excluding full-time students); education (no household members have at least Level 2 education, and no one aged 16-18 years is a full-time student); health and disability (at least one household member reported their health as being 'bad'/'very bad' or has a long-term health problem); and housing (the household's accommodation is overcrowded, with an occupancy rating -1 or less, or is in a shared dwelling, or has no central heating). is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. ;

For people aged over 75 years at time of the 2011 Census, approximated social grade was imputed based on household tenure.

We calculated age-standardised mortality rates (ASMRs) stratified by household composition and sex, separately for COVID-19 related deaths and other deaths. The ASMRs were standardised to the 2013 European Standard Population and can be interpreted as deaths per 100,000 of the population at risk during the analysis period.

We estimated Cox proportional hazard models to assess whether the risk of COVID-19-related death varies by household type (using living with one other older adult with as the reference category) after adjusting for the geographical factors, socio-economic characteristics and measures of health listed in Table 1 . These factors could confound the relationship between household composition and COVID-19-related mortality, as shown in Figure 1 . We estimated separate models for males and females, as the risk of death involving COVID19 differs markedly by sex [7] . When fitting the Cox models, we included all individuals who died during the analysis period and a weighted random sample of those who did not (5% of White people, and 20% amongst ethnic minority groups), and applied case weights to reflect the original population totals.

Note: When analysing whether household composition directly affects the risk of COVID-19 death, our effect of interest is A. In the mediation analysis, where we estimate the proportion of the ethnic disparity in COVID that is explained by living in a multi-generational household, the effects of interest are A+B We conducted a causal mediation analysis [16] to estimate the proportion of excess risk in ethnic minority groups which is attributable to living in a multigenerational household . As a measure of inequality in COVID-19 mortality, ethnicity-specific odds ratios for COVID-19 mortality were estimated using logistic regression models, fitted to males and females separately and adjusting solely for age in the baseline model. The proportion of the difference in COVID-19 mortality rates between ethnic groups mediated by living in a multi-generational household was then estimated as the Average Causal Mediated Effect (ACME) as a proportion of the age-adjusted difference in the probability of COVID-19 mortality, using a non-parametric approach [17] (see the Technical Appendix for more details). The mediator models and the full outcome model were adjusted for geographical factors (region, population density, urban/rural classification), socio-economic characteristics (IMD decile, educational attainment, social grade, household tenancy) and health (self-reported health and disability from the Census, pre-existing conditions based on hospital contacts) but not for overcrowding or housing type, as these are likely to be consequences of living in a multigenerational household rather than confounding factors (See Figure 1 ). Confidence intervals were obtained via bootstrapping, using 500 replications. All statistical analyses were performed using R version 3.5.

Characteristics of the study population are reported in Supplementary Table 2 in the Appendix. In our study population of 10,078,568 individuals in England aged 65 years or over who were not in a care home in 2019 and were still alive on 2 March 2020, just over half (53.9%) were female, the mean age was 75.2 years, and 93.9% reported being from a White ethnic background ( Table 2) . Over the outcome period (2 March 2020 to 28 July 2020), 27,989 (0.28%) died of COVID-19, and 123,551 (1.2%) died of other causes.

Compared with older adults living with one other older adult (n = 5,538,963), people living by themselves (n = 3,287,395) had a higher mean age, were more likely to be female, and tended to be more deprived. Older people living in a multi-generational household without dependent children (n = 987,306) and with dependent children (n = 199,112) were on average younger and were more likely to be from an ethnic minority group, live in London and large urban conurbations, and tended to be more deprived than older people living with another older adult. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. ;

Note: Linked 2011 Census and mortality registration data for people in England aged ≥65 years, excluding those living in a care home in 2019. The number of adults in the household was calculated as the number of people aged ≥25 years who lived in the household at the time of the Census, minus those who died between 27 March 2011 and 1 March 2020. Figure 2 shows that household composition varied substantially between ethnic groups. Among older people, just over 10% of those of White background lived in a multi-generational household, compared to over half of Bangladeshi or Pakistani background (58.7% and 58.8% respectively) and 45.8% of Indian background. The patterns were similar for males and females, although a larger proportion of females live by themselves (See Supplementary Figure 1 ).

Older people living by themselves were more likely to have died from COVID-19 over the study period than those living with another adult. There was a positive association between the risk of COVID-19 death and living a in multigenerational household. Both older males and females living a multi-generational household without school-age children were more likely to die from COVID - 19 is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. ;

Note: Deaths occurring between 2 March 2020 and 28 July 2020. 95% Confidence intervals are reported. Mortality rates are standardised to the 2013 European Standard Population.

Adjusting for individual-and household-level characteristics (including age, geographical factors, socio-economic characteristics and measures of pre-pandemic health) reduced the estimated differences in COVID-19 mortality rates between older adults living in different types households (Table 2) . However, even after adjusting for these characteristics, living in a multi-generational household, especially with children, remained associated with an increased risk of COVID-19-related death. Compared to living with another older adult aged 65 years or above, the rate of COVID-19related death was 1. 22 Hazard ratios compared to living in a household with one other older adult. Fully adjusted Cox regression models include geographical factors (region, population density, urban/rural classification), ethnicity, socioeconomic characteristics (IMD decile, household deprivation, educational attainment, social grade, household tenancy), health (self-reported health and disability from the Census, pre-existing conditions based on hospital contacts, number of hospital admissions, total days spent in hospital), a measure for overcrowding, and property type. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. ;

Living in a multi-generational household as a mediator for the disparity in COVID-19 death between ethnic groups Among people aged 65 years or over, those from all ethnic minority groups except Chinese were at greater risk of COVID-19 related death than those from the White population. Among people aged 65 years or over, those from all ethnic minority groups except Chinese were at greater risk of COVID-19 related death than those from the White population. 

Note: The overall height of the bar corresponds to the odds ratio (OR), relative to the White population, based on a logistic regression model adjusted for age. Error bars are 95% confidence intervals. The proportion of the age-adjusted ORs explained by living in a multi-generational household were calculated through a mediation analysis. The unexplained part corresponds to the ORs from a model adjusted for age, geographical factors (region, population density, urban/rural classification), socio-economic characteristics (IMD decile, household deprivation, educational attainment, social grade, household tenancy), health: (self-reported health and disability from the Census, pre-existing conditions based on hospital contacts, number of hospital admissions, total days spent in hospital)

Principal findings This paper makes two contributions to the research on COVID-19. First, we find that, among older adults, household composition is associated with COVID-19 mortality, even after adjusting for a range of socio-demographic factors and measures of health. Our results indicate that compared to those living in a two older adult household, older adults, especially females, living in a multigenerational household are at greater risk of COVID-19 death. Living alone is also associated with elevated COVID-19 mortality. Second, we find that living in a multi-generational household explains between 10% and 15% of the excess COVID-19 mortality risk for females of South Asian background, but very little for males or people from other ethnic groups.

Our results are consistent with emerging evidence that household size is associated with the risk of infection [18, 19] , and that older adults tend to be at greater risk of household transmission [20, 21] . Older people living in large household tend to live in multi-generational households, co-habiting with younger adults and children. There is some evidence that, amongst older adults, living with dependent children is not strongly associated with the risk of COVID-19 infection or adverse outcomes [22] . Whilst our results indicate that older adults living in a multi-generational household are at greater risk of COVID-19 death compared to those living with another older adult, we find is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. ; https://doi.org/10.1101/2020.11.27.20238147 doi: medRxiv preprint little difference in risk between older people living in a multi-generational household with or without young children.

Several studies have analysed ethnic differences in COVID-19 infection and mortality [3, 7, 6, 8, 4] . Although we focus on older adults only, we find that almost all ethnic minority groups were at higher risk of COVID-19 deaths compared to the White population, and that the differences were attenuated once we adjusted for a range of geographical factors, socio-demographic characteristics and comorbidities. We improve the existing evidence on ethnic inequalities in COVID-19 mortality by using a causal mediation approach to quantify the importance of living in a multi-generational household.

Our results suggest that older people are placed at increased exposure to infection by living with younger adults rather than young children. After adjusting for confounding factors, we find that the risk of COVID-19 death is similar amongst older adults living in a household with young children and those living in a household with younger adults only. The increased risk is likely to be driven by coresiding with younger adults, who have a higher risk of infection than older people [19] . Younger adults are likely to be at increased risk of exposure because of work, as evidence suggests that in England people who are working were at greater risk of infection compared to people not in employment, especially if they were working in patient or client-facing occupations [19, 23, 24] .

Older adults living by themselves were also found to be at greater risk of COVID-19 death than those living with another older adult. During the COVID-19 pandemic, older people living alone were more likely to have received help from carers, including informal helpers, than people living with another older adult [25] . These frequent contacts with people from different households could increase the risk of being exposed to the virus.

We find that living in a multi-generational household explains between 10% and 15% of the excess COVID-19 mortality risk for females of South Asian background, but very little for males, despite a similar proportion of them living in a multi-generational household. Women spend more time at home than men and still do the majority of unpaid housework [26] , which could increase the risk of household transmission.

The primary strength of our study lies in the use of a unique linked population-level dataset which combine the 2011 Census with death registration data and hospital records. Unlike data based solely on health records, our study dataset contains a broad range of information on demographic, socioeconomic, and household characteristics, including occupation. Unlike sample survey data, it contains millions of observations covering the entire population of interest, allowing us to examine both the association between household composition and COVID-19 mortality and also whether living in a multi-generational household explains some of the disparity in COVID-19 mortality between ethnic groups. We were able to examine differences between disaggregated ethnic minority groupings rather than high-level categories of South Asian, Black, and Other.

The main limitation of our study is that household composition is likely to be imprecisely measured. Whilst household composition is based on a detailed and accurate measurement taken in 2011, we could only identify changes since then due to death of household members or a move to a care home. Whist we took several steps to limit the measurement error, such as focusing on older adults, is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. ;  including only adults aged 25 or over and children aged 0 to 9 at the time of the census in our definition of household composition, our household composition measure may not reflect current living circumstances of everybody in our population of interest. To mitigate concerns about measurement error, we showed that our results are robust to using different definitions of household composition. Nonetheless, measurement error is likely to attenuate the explanatory power of household composition in our models. In addition, while we have used a causal mediation approach, our analysis remains based on observational data and therefore residual confounding is likely. Another limitation is that our statistical approach assumes that the effect of living in different types of household composition is the same across ethnic groups.

Older adults living in multi-generational households are at elevated risk of experiencing harms from COVID-19 compared to older adults living with people of the same age. However, there has been little focus on implementing effective interventions (such as creating plans to effectively isolate and improving ventilation within the home) to reduce transmission risk within the household [26] . Relevant public health interventions should be directed at communities where multi-generational households are highly prevalent. Living in a multi-generational household explains some of the excess COVID-19 mortality risk for females of South Asian background, but very little for males or people from other ethnic groups. Further research is needed to explain the difference in COVID-19 mortality between ethnic groups.

[27] P. Little, R. C. Read, R. Amlôt, T. Chadborn, C. Rice, J. Bostock and L. Yardley, "Reducing risks from coronavirus transmission in the home-the role of viral load," BMJ, vol. 369, p. m1728, 5 2020.

[28] NIHR, "Multimillion investment in new research projects to investigate higher COVID-19 risk among certain ethnic groups," 2020.

[Online]. Available: https://www.nihr.ac.uk/news/multimillion-investment-in-new-research-projects-toinvestigate-higher-covid-19-risk-among-certain-ethnic-groups/25333. 

Under the provisions of the Statistics and Registration Service Act 2007, the linked 2011 Census data used in this study are not permitted to be shared.

Following assessment using the the National Statistician's Data Ethics Advisory Committee (NSDEC)'s tool, we engaged with the UK Statistics Authority Data Ethics team and it was decided that ethical approval was not required. This is standard practice for analysing national Census data.

VN, NI, DA, CL and KK contributed to the study conceptualisation and design. VN lead the preparation of the study data and performed the statistical analyses. All authors contributed to interpretation of the results. VN drafted the manuscript. DA, NI, CG, VK, RM, MA, PG, AJ, AB, SG and KK contributed to the critical revision of the manuscript. All authors approved the final manuscript. VN is the guarantor for the study. The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.

The Average Causal Mediated Effect (ACME) of living in a multi-generational household for ethnic group k compared to the white group, ( ) is estimated as:

Where indicates if individual i lives in a multi-generational household, ℎ is the ethnic group and X is a vector of factors likely to confound the relationship between the mediator and the outcome. X includes geographical factors (region, population density, urban/rural classification), socio-economic characteristics (IMD decile, household deprivation, educational attainment, social grade, household tenancy), health: (self-reported health and disability from the Census, pre-existing conditions based on hospital contacts, number of hospital admissions, total days spent in hospital).

To estimate each component of ( ) ̅̅̅̅̅̅ , we use predicted probabilities based on logistic regression models.

The total estimated difference in probability of COVID-19 death between ethnic group k and the White ethnic group is given by:

The proportion of the difference in the probability to die from COVID-19 between ethnic groups that is mediated by living in a multi-generational household is given by the ACME, ( ) ̅̅̅̅̅̅ , as a proportion of the total effect ( ) ̅̅̅̅̅̅ . We then used this proportion to decompose the age-adjusted odds ratios. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. ; is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. ; https://doi.org/10.1101/2020.11.27.20238147 doi: medRxiv preprint Note: Main definition of multi-generational household: someone aged 65 years or over on 2 March in 2020 co-resided with at least one other adult aged more than 20 years younger (and at least 25 in 2011), or with at least one child. Def A1: we derived household composition in 2020 based on the number of adults aged 20 years (instead of 25 years); Def A2: multigenerational household as household with someone aged 65 years or over in 2020 co-resided with at least one other adult aged more than 15 years (instead of 20 years) younger. Proportion of difference in COVID-19 mortality between ethnic group mediated by living in a multi-generational household is estimated as the Average Causal Mediated Effect (ACME) as a proportion of the age-adjusted difference in the probability of COVID-19 death. The ACME is derived based on models that adjust for geographical factors (region, population density, urban/rural classification), socio-economic characteristics (IMD decile, household deprivation, educational attainment, social grade, household tenancy), and health: (self-reported health and disability from the Census, pre-existing conditions based on hospital contacts).

. CC-BY-NC-ND 4.0 International license It is made available under a perpetuity.

is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted December 2, 2020. ; https://doi.org/10.1101/2020.11.27.20238147 doi: medRxiv preprint

Updating ethnic contrasts in deaths involving the coronavirus (COVID-19)

Disparities in the risk and outcomes of COVID-19

Black, Asian and Minority Ethnic groups in England are at increased risk of death from COVID-19: indirect standardisation of NHS mortality data

Ethnic and socioeconomic differences in SARS-CoV-2 infection: Prospective cohort study using UK Biobank

The impact of ethnicity on clinical outcomes in COVID-19: A systematic review

Ethnic minority groups in England and Wales -factors affecting the size and timing of elevated COVID-19 mortality : a retrospective cohort study linking Census and death records

OpenSAFELY: factors associated with COVID-19

Ethnic differences in COVID-19 infection, hospitalisation, and mortality: an OpenSAFELY analysis of 17 million

Ethnicity facts and figures: Families and households

Living with parents or grandparents increases social capital and survival

Social Capital, Social Cohesion, and Health

Descriptive analysis of social determinant factors in urban communities affected by COVID-19

Covid-19: Breaking the chain of household transmission

Department for Communities and Local Government

Welsh Index of Multiple Deprivation (WIMD) 2014

A General Approach to Causal Mediation Analysis

Identification, inference and sensitivity analysis for causal mediation effects

Socio-demographic heterogeneity in the prevalence of COVID-19 during lockdown is associated with ethnicity and household size: Results from an observational cohort study

Antibody prevalence for SARS-CoV-2 in England following first peak of the pandemic: REACT2

Household secondary attack rate of COVID-19 and associated determinants in Guangzhou, China: a retrospective cohort study

The household secondary attack rate of SARS-CoV-2: A rapid review

Association between living with children and outcomes from COVID-19: an OpenSAFELY cohort study of 12 million

Occupation and risk of severe COVID-19: prospective cohort study of 120,075 UK Biobank participants

Risk of hospital admission with coronavirus disease 2019 in healthcare workers and their households: nationwide linkage cohort study

Older and 'staying at home'during lockdown: informal care receipt during the COVID-19 pandemic amongst people aged 70 and over in the UK

Gender Divisions of Paid and Unpaid Work in Contemporary UK Couples

Def A1: we derived household composition in 2020 based on the number of adults aged 20 years

multi-generational household as household with someone aged 65 years or over in 2020 co-resided with at least one other adult aged more than 15 years (instead of 20 years) younger. Hazard ratios compared to living in a household with one other older adult. Fully adjusted Cox regression models include geographical factors (region, population density, urban/rural classification), ethnicity, socio-economic characteristics (IMD decile, household deprivation, educational attainment, social grade, household tenancy), health (self-reported health and disability from the Census, pre-existing conditions based on hospital contacts, number of hospital admissions, total days spent in hospital

Note: Proportion of difference in COVID-19 mortality between ethnic group mediated by living in a multi-generational household is estimated as the Average Causal Mediated Effect (ACME) as a proportion of the age-adjusted difference in the probability of COVID-19 death. The ACME is derived based on models that adjust for geographical factors (region, population density, urban/rural classification), socio-economic characteristics (IMD decile, household deprivation, educational attainment, social grade, household tenancy), and health: (self-reported health and disability from the Census, pre-existing conditions based on hospital contacts)

Supplementary Table 5: Proportion of difference in COVID-19 mortality rates between ethnic groups mediated by living in a multi-generational household using different definitions of household composition