Data on socio-economic status of patients and deaths with COVID-19 are not systematically collected and are still very rare. Evidence of a higher risk of dying from COVID-19 for individuals of low social classes is however slowly popping up.
In a previous post I argued that there are strong reasons to expect that COVID-19 mortality rates are higher among individuals of the lower social class. In the absence of data on the socio-economic characteristics of those who have died because of Covid19 my claim rested on indirect evidence. The core idea was that COVID-19 mortality risk can be conceived as the result of the product of three different risks: the risk of infection, the risk of developing a severe disease from coronavirus and the risk of dying/recovering if severely ill with COVID-19. Each of this risk is likely to be higher for individuals of the lower class. In particular, we know that people with underlying pre-existing medical conditions are more vulnerable to becoming severely ill with COVID-19. We also know that the incidence of chronic diseases tends to be higher among those who are low-educated. This is a well-documented fact and worst health conditions are probably the key link between SES and risk of higher mortality because of COVID-19.
The new evidence on SES and COVID-19 can now be grouped in three categories (in declining order with respect to their size): aggregate data on mortality (and infection) rates by neighborhood, data on contagious by occupations and direct evidence on mortality rate by occupations.
I shortly discuss and provide some references on each of them below.
COVID-19 and neighborhoods
This is by large the most popular type evidence of a SES gradient in the COVID-19 mortality rate. Many newspaper articles show that the risk of mortality because of COVID-19 is higher in poorest and most deprived neighborhood in New York, Chicago , Paris and Madrid. The limit of this evidence, in particular in the case of Madrid that I know best, is that nursing and care homes are often located in the suburbs and not in the richest neighborhoods. The lower mortality rates in the richest and poshest areas in large cities might, therefore, also reflect the lower presence of nursing and care homes that are the big trouble spots of this pandemic.
COVID-19 and risk of infection by occupation
The evidence in this respect is much scarcer. There are now two nice graphs on workers who face the highest risk of COVID-19 infection for US and UK. With the exclusion of health professions low-skilled jobs as cashiers, couriers and workers in the energy sector and construction, are among the professions with the highest risk of infection.
There is a pre-print study on work related transmission in the emerging coronaviral pandemic in Hong Kong, Japan, Singapore, Taiwan, Thailand, and Vietnam. Two findings seem relevant to me. First work-related transmission played a substantial role in the early phase of the outbreak and, with the exclusions of health care workers, the occupations with the most cases of transmissions were drivers and transport workers (18%), services and sales workers (18%), cleaning and domestic workers (9%). The N of the study is however rather small and it is difficult to generalize these findings to other countries with different occupational structures and employment conditions.
COVID-19 and mortality rates by SES
I know one study that presents direct evidence of the relationship between deaths related to COVID-19 and occupation (and thus social class). A recent statistical bulletin of the ONS in UK presents an analysis of deaths involving the coronavirus (COVID-19) in different occupational groups among those aged 20 to 64 years in England and Wales. A major finding of this study is that “compared with the rate among people of the same sex and age in England and Wales, men working in the lowest skilled occupations had the highest rate of death involving COVID-19”.
While it is not clear whether it is occupational exposure that determines the higher risk of mortality among elementary occupations, the evidence of this study can be read as indicator of a clear class divide in COVID-19 mortality, being the upper class less affected.
It seems very reasonable that COVID-19 hits more strongly the lower classes. The available evidence supports this claim but we need more studies and data, as those on which the ONS bulletin is based, to further substantiate it.