The initial estimates of the case fatality rate of coronavirus disease 2019 (COVID-19) from China and the published modelled estimates both show a very strong age-dependence.1, 2 In the UK, this pattern has been interpreted in public health terms as advice to cocoon (ie, isolate) those older than 70 years and those with underlying health conditions—but is this the right age cutoff?
Applying the infection fatality rate ratios from new estimates (which assume a constant attack rate by age) to the age structure of the population of the UK,3 we can see how many deaths we would expect in each age group if there were 1 million infections (table ). This shows that 70% of all deaths are in the over-70-years age group, so it is important that they are protected. However, nearly two thirds (64%) of the remaining deaths occur in the 60–69 years age group. This age group is not being particularly protected and includes many who are working on the frontline. Indeed, health-care workers have even been encouraged to come out of retirement to assist.
Table.
Estimated deaths by age group if 1 million people in the UK population are infected with SARS-CoV-2
Proportion of UK population (%) | Infection fatality ratio (%) | Number of deaths if 1 million population infected | Proportion of deaths | Proportion of deaths if over 70s successfully cocooned | |
---|---|---|---|---|---|
0–9 | 12% | 0·00161% | 2 | <1% | <1% |
10–19 | 11% | 0·00695% | 8 | <1% | <1% |
20–29 | 13% | 0·0309% | 41 | <1% | 1% |
30–39 | 13% | 0·0844% | 112 | 1% | 3% |
40–49 | 13% | 0·161% | 206 | 2% | 6% |
50–59 | 13% | 0·595% | 803 | 8% | 25% |
60–69 | 11% | 1·93% | 2054 | 19% | 64% |
70–79 | 8% | 4·28% | 3535 | 33% | .. |
80+ | 5% | 7·80% | 3853 | 36% | .. |
Based on the Chinese data,1 each death corresponds to about two critical cases (needing intensive care) and six people who require hospitalisation. Both for humanitarian reasons and to prevent overload of the health service, shouldn't we be protecting people older than 60 years and ensuring that those in that age group who are currently not working from home are moved to jobs with minimal person contact, whether it is in the health service, schools, government, or the private sector?
Acknowledgments
My partner is older than 60 years and works in the health service. I declare no other competing interests.
References
- 1.The Novel Coronavirus Pneumonia Emergency Response Epidemiology Team Vital surveillances: the epidemiological characteristics of an outbreak of 2019 novel coronavirus disease (COVID-19)—China, 2020. China CDC Weekly. 2020;2:113–122. [PMC free article] [PubMed] [Google Scholar]
- 2.Verity R, Okell LC, Dorigatti I. Estimates of the severity of coronavirus disease 2019: a model-based analysis. Lancet Infect Dis. 2020 doi: 10.1016/S1473-3099(20)30243-7. published online March 30. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Office for National Statistics National population projections: 2018-based. Oct 21, 2019. https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationprojections/bulletins/nationalpopulationprojections/2018based