A well-researched piece by Dr Malcolm Kendrick, which I encourage all to read, was published this week. It examined the reasons why countries are seeing more cases of Covid19 but fewer deaths.

Statistics can be bamboozling and are often used to confuse people. This is an attempt to simplify. There are two main parameters that can be measured when looking at the fatality rate of a virus (or any infective agent). One is the case fatality. This is the number of people who die, divided by the total number of cases of people with symptoms from the virus expressed as a percentage. For example, if ten people die and there are 1000 cases then the case fatality rate is 1% (one fatality per 100 cases).

The other is infection fatality rate (IFR) which is the number of deaths divided by the number of identified infections – whether people have symptoms or not. This percentage will be much lower as it includes those without illness. The more tests that are done, the higher the number of infections identified.

The case fatality rate will always be higher than the infection fatality rate. Why? Because only some who have the virus can be defined as a “case” – defined as having symptoms. An even smaller number have symptoms which lead them to seek medical attention. A smaller number still have symptoms requiring hospitalisation.

In the early stages of Covid19 most tests were being done on those who were sick and in hospital. Increasingly more tests have been done on people in a variety of situations. As more tests are done, more infections are found. Many, indeed, most of these people do not have any infective symptoms. They would not know they had the virus unless tested. Dwayne Johnson (The Rock) and his family are a good example.

Let’s look at some examples on Worldometers from September 4. France reported 8550 new cases and zero deaths. Belgium reported 630 news cases and two deaths. The UK 1813 cases and 12 fatalities.

Numbers quoted by Kendrick show that Iceland, which has done the most tests per capita, has an infection fatality rate of 0.16%.

The case fatality rate in Sweden currently is 0.3% and in France 0.4%. In the UK it is 0.9% and falling. In fact, it is falling in most places. Some writers are puzzled as to why the deaths rates are falling. Some have wondered if the virus is getting less lethal. This can’t be ruled out as disease patterns change.

The main reason the initial figures over-estimated the fatality rate, is that it grossly under-estimated the total number of infections. Yet a paper co-written by Dr Anthony Fauci and published in the New England Journal of Medicine on February 28 concluded “This suggests that the overall clinical consequences of Covid-19 may ultimately be more akin to those of a severe seasonal influenza”.

The emerging numbers suggest that Fauci et al were correct.

Yet to now suggest that Covid19 is not much worse than seasonal flu may see you get a knock on the door at 3am!

Here in Australia it is difficult to fathom where we are going. With thousands of cases each day the French President has declared the county will not lock down. With under 100 cases per day Victoria still has a curfew. With no community cases for over 100 days WA still has closed borders to the rest of Australia.

In Australia there have been 753 deaths. Of these only 40 have been aged under 70. The average life expectancy is 82 and this is the median age of death with Covid19. It is also important to note that not all deaths with the virus were caused by the virus.

We get a daily update of infections, which is presented as “cases”. The two are not identical.

Early predictions were for 150,000 deaths and a lack of ICU beds by April 4. Lockdown supporters will claim the results as proof of the success of government policy. It is very easy to claim, credit for preventing that which may never have occurred.

The biggest failures world-wide have been the inability to protect aged care facilities. Interestingly though, total number of deaths in these facilities are down in Australia compared to last year.

Meanwhile the effects on individuals, families, businesses and children of lockdowns are seemingly ignored. Missing school has long term consequences. Confining people to their home under fear of arrest has consequences. Livelihoods destroyed and businesses closing, with associated job loss has consequences. Separating people from their family and friends has consequences. In 2018 there were 3046 deaths by suicide. This figure has been estimated to increase by 15-50% each year for the next five years. A culture of fear and heavy-handed action by police has consequences.

As I have written before, in clinical practice doctors are obligated to outline side effects from any proposed treatment. Surgeons must explain potential complications from procedures. Yet public health doctors are not held to the same standard.

Final word must go to Ronald Brown who published “Public health lessons learned from biases in coronavirus mortality overestimation” . This has exposed why fatality rates were overestimated – infection fatality rate was confused with case fatality rate.

“In testimony before U.S. Congress on March 11, 2020, members of the House Oversight and Reform Committee were informed that estimated mortality for the novel coronavirus was ten-times higher than for seasonal influenza”. It continues “Results of this critical appraisal reveal information bias and selection bias in coronavirus mortality overestimation, most likely caused by misclassifying an influenza infection fatality rate as a case fatality rate”.