Coronavirus: Italy’s dreadful mortality is not our destiny

A policeman stops a returning passenger at Brisbane Airport on Thursday. Picture: AAP

While the Prime Minister is right to emphasise that it is still early days, there are good reasons to ­believe Australia is not headed towards the kind of catastrophe that has devastated China, Italy and Spain, both in terms of the spread of COVID-19 and even more so in terms of the fatalities it causes.

That makes it important to question the need for measures that are ever more drastic and restrictions on traditional freedoms that are more drastic yet.

It is true enormous uncertainties persist. However, even taking all the caveats on board, there are encouraging signs COVID-19’s rate of spread in Australia has ­declined in the past two weeks.

Indeed, a standard indicator of the rate of spread — the number of days it takes for the number of confirmed cases to double — has increased from three days to nearly eight, signalling a slowing in the epidemic. While the spread of the disease has also slowed in Italy, the deceleration has been less than half that in Australia, and has occurred when the contagion already affects a much larger share of the population.

To say that is certainly not to claim the epidemic is over. Once the influx of cases contracted overseas has been stemmed, whether those favourable trends persist depends on maintaining low transmission rates within the community. However, even if they did persist, the caseload in Australia would continue growing but it would tend to a level (in technical terms, an asymptote) that is less than a sixth the level it would have reached had Australia’s experience mimicked Italy’s.

Moreover, it would approach that peak at a much more gradual pace, in terms of the growth in ­absolute numbers, than characterised the epidemic in Italy, though ongoing increases in testing will impart an upward bias to the measured growth rise in morbidity (that is, numbers infected).

The differences in mortality between Australia and the worst-affected countries are likely to be even greater than those in morbidity. By and large, the spread of COVID-19 in the population has followed a similar pattern internationally, in which a slow start gives way to explosive growth before reaching a limit at which growth peters out.

There is, however, a stark contrast between countries such as Italy, Spain and France, where mortality and morbidity have risen steeply and in step, and others such as Germany, The Netherlands, Sweden and Singapore, where the increase in the number of cases has greatly outstripped that in deaths.

That contrast is partly due to differences in reporting regimes and in the time that has elapsed since the crisis began. But even among countries at reasonably similar phases in the epidemic, morbidity rates, calculated as a share of the population, vary only fivefold, while mortality rates vary by a factor of 20.

There is, in other words, a much greater gap between the best and worst-performing countries in the extent to which COVID-19 has proven fatal than in the extent to which it has spread.

Reflecting that gap, while mortality rates are very high in Italy, France and Spain, the fatalities in Sweden, Switzerland, Germany, The Netherlands and Iceland remain small compared with daily death rates from other causes. And adjusting for the later start of the epidemic in Australia, our death rate from COVID-19 is among the world’s lowest, despite the disastrous errors made in handling cruise ships.

It is much too soon to rigorously disentangle the myriad causes of those differences. Nonetheless, it is clear that differences in population health are a significant factor — and the highly skewed pattern of the condition’s incidence makes the impact of those differences all the greater.

Thus, taking the countries for which there is detailed data on the age composition of the population affected by COVID-19, more than 80 per cent of the fatalities have occurred among people aged 70 and older, with those aged at least 80 accounting for half of all deaths, despite comprising less than 15 per cent of cases.

Additionally, the risk of death, both in those age groups and in others, seems to be materially increased by comorbidities, especially those associated with diseases of the respiratory system.

It is therefore unsurprising that fatality rates are significantly higher in countries where the very old make up a relatively large share of the population and are already likely to be in poor health. For example, 7 per cent of Italy’s population is aged 80 and older, as compared with 3.9 per cent of Australia’s; Italians are 1.6 times more likely to smoke daily than Australians, with smoking prevalence, and the illnesses it causes, being particularly high among the elderly; and the overall burden of disease, measured in terms of the disability it imposes, is twice as great in Italy as it is in Australia.

A broad range of other factors then compound those differences, pushing Australia towards the low end of the COVID-19 fatality rates. Aged-care homes, where ­fatalities have been appallingly high in Italy, France and Spain, are relatively tightly regulated in Australia, and while our residential aged-care facilities have many deficiencies, their health and safety levels are usually more than respectable by global standards.

Moreover, Australian vaccination rates against seasonal ­influenza are high, which is important because it both materially affects the respiratory health of vulnerable groups and highlights widespread voluntary compliance with health advice.

Finally, and more generally, the average distance between homes in Australia is about twice that in the US and nearly four times that in Europe. Particularly with the social-distancing restrictions that are now in place, our settlement pattern reduces social interaction and limits contagion.

None of those factors means we can relax the restrictions, although placing greater reliance on testing, tracking and tracing, targeted at protecting highly vulnerable groups, seems desirable.

But that shift cannot be made overnight, and in the meantime the current restrictions ought to make the crisis manageable within the health system’s capacity constraints.

That is all the more the case as hospital capacity is expanded. And just as capacity is being increased, the restrictions are curtailing the incidence of conditions that normally consume scarce hospital resources, including drink-driving, sporting injuries and complications from elective surgery.

There is consequently little basis, at least in the data as it stands, for the incessant move to clampdowns that, in some cases, are absurdly draconian. As well as being unnecessary, heavy-handed measures may erode community support for the restrictions, ­undermining our high levels of voluntary compliance. With Australians already making extraordinary sacrifices, this is a time for prudence, not panic.