Lockdowns essential for suppressing Covid but not long term solution

Returning to Covid lockdowns in New Zealand, in particular in Auckland, has meant a return to arguments over whether they are effective or a sustainable means of reducing deaths and long term health problems inflicted by the virus.

People lacking in expertise pushing for so-called ‘herd immunity’ using flawed analysis based on limited data, even if well intentioned, adds to a lot of misinformation.

But while lockdowns are a short term means of preventing large scale infections and deaths, and by preventing barely adequate at the best of times health systems from becoming overloaded. But:

“It is clear that this is not seasonal flu.”

“No country can just ride this out until we have a vaccine.”

Political pundits like Matthew Hooton are not knowledgeable enough about viruses to ton use their usual media ‘opinion’ advocacy to advise us what is the best approach to dealing with Covid.

In Hooton’s latest “armchair epidemiological reckons, I emphasised that he does not have the skills to analyse epidemiological data…he unfortunately makes rookie mistakes again.”

Dr Jin Russell takes issue with the opinion column by Hooton. This gives more insight into dealing with the pandemic than a political pusher.

In my last set of tweets on @MatthewHootonNZ‘s armchair epidemiological reckons, I emphasised that he does not have the skills to analyse epidemiological data. In his latest Herald piece, he unfortunately makes rookie mistakes again.

He includes a table of the 1330 covid cases in NZ; and describes a hospitalisation rate of 4%; with no deaths under 60 years; and “only” a 30% chance of dying in the 80+ group.

I think that most people would see a one in three chance of people over 80 dying from Covid as a very good reason to try to minimise it’s spread. Quarantining all the elderly only is not a viable option, nor i think socially acceptable, nor practical.

The gist is he’s minimising the risk of covid based on NZ MOH data; but this is really flawed.

Flawed in two ways:

1. The only variable he is taking into account in his mortality projection appears to be Age; and

2. Because he accounts only for mortality and not for morbidity associated with Covid-19. Let’s explore these.

Let’s explore these.

1. The only risk factor he highlights is Age. Yes, increasing age increases risk of mortality from covid, as we can see even from our small NZ sample. But that’s not the only risk factor for dying from covid.

This July paper published in Nature analysed other risk factors – Factors associated with COVID-19-related death using OpenSAFELY

Comorbidities such as diabetes, obesity, asthma, and others are known to correlate with increased risk of mortality from covid. Let’s look at these risk factors for the NZ population.

Diabetes: We have very high numbers of people with diabetes in NZ. An estimated 200,000 people in NZ have diabetes; with the prevalence in Māori & Pacific persons three times higher than NZ Europeans.
– MOH: About diabetes

Obesity: New Zealand has the 3rd highest obesity rate amongst adults in the OECD, with 1 in 3 adult NZers obese, and 1 in 10 children. Once again, this is disproportionately found amongst deprived communities; Māori and Pacific families.

Asthma: NZ has one of the highest rates of asthma in the world; the Asthma Foundation estimates 597,000 NZers take medication for asthma (1 in 8 adults, higher for children) with a very high burden of respiratory admissions amongst children amongst deprived families.

The Nature paper also found that people of “Black” and “South Asian” ethnicity were at increased risk of mortality. It’s important to realise that so far our current NZ covid cases are overwhelmingly amongst Europeans.
– see Stats NZ: COVID-19 data portal

In epidemiological terms, we would refer to our NZ dataset of a miserly 1665 cases (cases! deaths only 22) to be a “biased” sample; with a hopelessly small sample size. In other words, we are unable to draw any accurate predictions on how covid would impact our population from the MOH data we have.

We can’t look at our MOH data and make inferences that the virus would have this many in hospital, this many dead or chronically affected, etc, as the sample is too small, and not representative of how covid impacts populations as a whole

This is why review of the literature, and understanding of other factors is so important.

It’s not just deaths that are a problem. There are serious long term health implications for people who get Covid.

Let’s talk about morbidity from covid – what complications can it cause?

A paper published in Nature Medicine describes non-pulmonary complications from Covid-19. If it doesn’t get you in the lungs, how does it harm you? Amongst those hospitalised or seriously unwell, 30% had acute cardiac muscle injury, up to 30% acute kidney injury, 6% stroke, up to 52% signs of liver injury, 8-9% confusion or impaired consciousness.

figure1

See Nature Extrapulmonary manifestations of COVID-19


It is clear that this is not seasonal flu.

On top of that, there is increasing evidence of a post-covid syndrome, with chronic breathlessness and fatigue.

So far, we have understood that we have a very high burden of comorbidities that would make NZers more likely to die or do poorly compared to other countries, and that it would disproportionately affect our Māori, Pasific and South Asian communities. What about other factors?

Hooton doesn’t discuss this at all – a really, really important variable to consider – our healthcare capacity. In March, prior to lockdown, NZ had a total of 153 ICU beds.
RNZ (March 2020) – 153 intensive care beds in country – survey

And, of those 153 beds, just to drive the point home, only 24 were at Auckland City Hospital. Of the 24 ICU beds at our country’s largest hospital, only 6 were isolation beds. Those beds are not empty all the time, they run close to capacity.

So…we had to lockdown.

The number of ICU beds was supposed to be tripled – RNZ (May 2020) ICU beds increase as ministry tries to triple capacity

I’m not sure if that has happened yet, but even if we had the target 358 beds, that wouldn’t even get us close to the figure we would need if things got out of hand.

Our healthcare workforce is VERY thin and PPE stocks are in short supply internationally. I work in paediatrics. During Level 4 lockdown, there were plans to completely reorganise health services to treat covid patients. Thank goodness we didn’t need to go there.

To sum up – Hooton has a LONG way to go to draw any valid conclusions from our MOH data on covid. To form great public health policy, you need more skills than this. You need local understanding of our inequities, health care capacity, and distribution of comorbidities.

You need to be informed by the literature, and come to considered judgements. This is very sloppy opining, what a shame he didn’t contact some of the many very lovely, very experienced epidemiologists and infectious disease experts within his own institution.

As well as business and economic experts.

Covid is too serious and too complex for the pundit political pusher approach.


See also, from WHO Director-General’s opening remarks at the media briefing on COVID-19 – 21 August 2020

Globally, there are now more than 22 million reported cases of COVID-19, and 780,000 deaths.

But it’s not just the numbers of cases and deaths that matter. In many countries, the number of patients who need hospitalization and advanced care remains high, putting huge pressure on health systems and affecting the provision of services for other health needs.

Several countries around the world are now experiencing fresh outbreaks after a long period with little or no transmission.

These countries are a cautionary tale for those that are now seeing a downward trend in cases.

Progress does not mean victory.

The fact remains that most people remain susceptible to this virus.

That’s why it’s vital that countries are able to quickly identify and prevent clusters, to prevent community transmission and the possibility of new restrictions.

No country can just ride this out until we have a vaccine.

A vaccine will be a vital tool, and we hope that we will have one as soon as possible.

But there’s no guarantee that we will, and even if we do have a vaccine, it won’t end the pandemic on its own.

We must all learn to control and manage this virus using the tools we have now, and to make the adjustments to our daily lives that are needed to keep ourselves and each other safe.

So-called lockdowns enabled many countries to suppress transmission and take the pressure off their health systems.

But lockdowns are not a long-term solution for any country.

We do not need to choose between lives and livelihoods, or between health and the economy. That’s a false choice.

On the contrary, the pandemic is a reminder that health and the economy are inseparable.

But there doesn’t seem too be many experts on both epidemiology and economic matters.