A demographic study on COVID-19 infection outcomes

Abstract

It is difficult to obtain good quality, accurate data on COVID-19. Demographic and epidemiological data from various agencies are classified and grouped in a variety of different ways, at differing levels of detail; this making deriving useful information from raw data more difficult.

This study attempts to provide some meaningful data on COVID-19 infection and outcomes, and the extent of national COVID-19 infection. From the results estimated (based on information from the Diamond Princess, and statistics from the UK) it is possible to estimate the number of people infected in any country.

Case study

Initial data to provide base information for computation has been derived from records from the Diamond Princess: a cruise ship quarantined at Yokohama, Japan in Feb 2020

The Diamond Princess is possibly the only case with data records of infection numbers and deaths across each age group for all passengers. Passengers were confined to their cabins, unable to leave the ship. Thus clear patterns have emerged from the data obtained. Results are unaffected by unknown virus vectors.

For approximately three weeks all passengers on the ship were quarantined on board from 5th Feb. The last passenger infection was recorded 14th Feb. It is reasonable to assume that the quarantine worked: most passengers were infected before the quarantine commenced. The only infections that took place amongst passengers were those passengers that shared a cabin. Almost all passengers were tested for COVID-19 infection.

From the total of 567 passengers infected, as at 18 April 2020 there were 14 deaths. Of these, the age decade is known for 12 victims (all but one was aged 70 or above), and the gender is known for 13 victims (10 male, 3 female).

Diamond Princess quarantine

	Passengers	Crew	Total
Average Age	69	36
On Board	2666	1045	3711
Infected	567	145	712
Deaths	14	0

Age of infected passengers

Age	Total Cases	Percentage
00-09	1	6%
10-19	2	9%
20-29	20	6%
30-39	23	5%
40-49	25	8%
50-59	49	12%
60-69	177	19%
70-79	234	23%
80-89	52	24%
90-99	2	18%
Total	531	100%

Approach

Using the age-gender grouping with the most cases, and the most fatalities: males aged between 70 and 79 years. Because information on two of the fatalities is unknown, using computational analysis on the various possibilities and then comparing the ratios from this data with the most recent UK COVID death figures, the scenario with closest match was selected to estimate the infected population. The best match of scenario ratios to UK ratios differed by 0.6%. With the scenario selected, an estimate can be made of the total national COVID-19 infected population. Results obtained assume a uniform distribution of infection across the population, but does account for the populations of each age group.

Results

The model used is one of the more pessimistic in terms of a good outcome for males aged 70 and above. Using this model, the overal UK national death rate across the entire population is 1%. It is based on near-complete data, which is not available from UK public sources. For example, NHS England only record COVID-19 deaths which occur in hospitals. The National Records of Scotland state that 56% of deaths in Scotland occur at a hospital.

Number infected in the UK

NOTE: this figure only represents an estimate of infection at roughly the end of March. Aside from the unproven validity of the model, the figure is inaccurate and outdated because-:

• It is based on the latest ONS data which is from 17th April 2020.
• The ONS data only includes hospital deaths. It does not include deaths at home or in residential homes.
• For a fatal case, the average time between infection and death is 14 days. This figure estimates the infected figure from approx. two weeks before 17th April 2020.

Deaths outside hospitals

As official figures published today indicate that a large number of deaths have occured in care homes, cases outside hospital should be considered. The best official indicator is from National Records of Scotland. It's latest findings state that 56% of deaths occured at hospitals. Extending the proportion of hospital / non-hospital deaths from Scotland across the UK gives an estimate of 3.01 million infected in the UK.

Applying latest NHS figures

Including the latest NHS figures (up and including Monday 27th April) to gives a UK infection estimate of:

4,723,090

That is, just over 4.7 million - 7.0% of the UK population.

Survival Rates by age group and gender

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28th April 2020