Category: Data & science

Simon Thornley

16/03/2021

Over a year now into New Zealand’s covid-19 saga, what can we learn from the experience of intensive care units? In the early days, protection of intensive care units and the scarcity of ventilators was a major factor shaping covid-19 policy.

New Zealand students were busy building ventilators, intensive care capacity was a major government concern, and became a key component of the elimination strategy.

The thought, early on, was that covid-19 was a completely new disease and that early mechanical ventilation was necessary in a patient’s treatment to give them a good chance to make it through. Since mechanical ventilation is a medical treatment, it must make things better, acting like a kind of super bellows, taking over when the patient ran out of steam, buying them time as their body beat back the virus.

The reality of intensive care experience has been somewhat different. It is well known that ventilators inflate the lung in an unnatural way, causing ventilator induced lung injury. They are far from a benign intervention and must only be applied sparingly.

Unfortunately, a certain level of jargon is necessary to dive deep into the ventilator story. A crucial measure of lung disease that is important in deciding to ventilate a sick or deteriorating patient is the ability of the lungs to soak up oxygen, known as the Pa0₂:FiO₂ ratio. This is the ratio of oxygen pressure, measured from a patient’s artery relative to the percentage of oxygen being delivered, usually via a mask. This ratio indicates the ability of a patient’s lung to deliver essential oxygen to the body. Usually, values of 150 mmHg to 200 mmHg indicate the need for a ventilator. Early opinions from Wuhan, from Chinese anaesthetists, recommended early intubation, with patients having values as low as 300mmHg indicating need for a tube. In some hospitals, the milder form of breathing support, non-invasive ventilation, was not used due to the fear of spreading the virus to staff. In other areas, such as the US, financial incentives to ventilate were operating.

Early mechanical ventilation has been a spectacular failure, with the best evidence now showing that it did more harm than good. A recent study, published in January 2021, now has the wash-up from experience with 10,362 patients who have had covid-19 in the UK and been in through a critical care unit. These are covid-19 patients at the severe end. Almost 38% (3,933/10,362) of subjects died. The critical comparison was between those who were ventilated and those who were not. For those who were ventilated early, at low severity of lung disease (Pa0₂:FiO₂ = 300mmHg), they had almost twice the rate of death, compared to those who weren’t, after accounting for all other factors. In fact, the most surprising finding was that for any level of lung impairment, those who were ventilated were more likely to die than those who were not. A conservative estimate of the importance of this finding, indicates that it accounted for about 15% or 1/7 of all the study deaths.

Naysayers may point out that the study was an observational one – not a trial – and that the results may be explained by doctors spotting unrecorded adverse factors that led them to put tubes down patients’ throats. An interview with North American intensive care doctors, however, contradicts this interpretation. Doctors spoke of asking patients to get off their mobile phones so they could put them on a ventilator. This was unusual practice, created by the fear of a new disease with an unpredictable course. Ultimately, it was learning to do less, rather than more which reduced mortality rates.

This created a sort of medical self-fulfilling prophecy of a deadly virus. The simplistic fixation on ventilators and the perceived need for them led to excessive use and premature deaths. Together with exaggeration of recording of covid-19 deaths, a vicious circle of fear took hold. The finding that Italy had ~10% of participants in a screening study of several regions of the country with antibodies for SARS-CoV-2 in September 2019, with no excess mortality at the time, strongly indicates that the healthcare and societal response, including lockdowns, were deadlier than the virus ever was.

Simon Thornley

28 Feb 2021

New Zealand descends into another lockdown abyss just as I am now questioning the very foundations of the covid story.

Recently, I have pointed to evidence that covid was around in Europe before Wuhan. Since we were apparently living with covid in Europe without excess mortality or catastrophe, this seems at face value to suggest that we had lived with the virus and can do so again.

Another matter is that we have shifted how we define virus related factors, and this is causing us to believe SARS-CoV-2 is more serious than it is. Definitions are a cornerstone of epidemiology and the collection of scientific data. Death seems to be a clear-cut event in a person’s life but determining the cause of death is a surprisingly difficult process.

As Dennis De Nuto so beautifully illustrated in the Ocker flick, “The Castle”, definitions matter. Responding to the judge with “it’s the vibe, your honour” when alleging a constitutional law breach doesn’t quite cut it. While there is almost always uncertainty about causes of death and classification, this uncertainty has been stretched to breaking point in New Zealand’s covid-19 saga. The most recent death is illustrative.

We learned that an individual had been in quarantine. They were then transferred to North Shore Hospital for a serious non-covid illness and later tested positive for covid. The patient later died. A few days later, the death was considered another official NZ covid death. On the face of it, without further information, this does not indicate to me a death caused by infection with SARS-CoV-2. At no point in the article are we told that the individual had the disease that the virus is alleged to cause: a lung infection. When the reporter quizzed the Director General, Dr Ashley Bloomfield, for justification of the Ministry’s classification the response was revealing: ‘…we have been very inclusive in our approach of categorising deaths as covid-19-related…”. He went on to explain, “You might recall when we had a number of deaths last year sadly related to aged residential care. A number of those people had actually not been swabbed because of the nature of their conditions but they were categorised as probable cases because of their symptoms…”

We have learned two important things from these statements. In the first case, if you want to classify as a covid death you do not need evidence of a lung infection. In the second, when referring to the rest home deaths, you do not even need a positive PCR test. There was no further evidence related to autopsy or other clinical findings or investigations.

The next revelation came in how this decision making was justified. Bloomfield’s response was “Most countries are doing this, for example in the UK they categorise everyone who dies within 28 days of being hospitalised with covid-19 as … a COVID-19-related death.” Essentially, everyone else is doing it, so… why not?

It would be weird and totally unhelpful if this was the approach to any other disease. It’s even worse for Covid because we are now in Auckland’s fourth lockdown – justified based on saving lives from infection. It is now questionable that New Zealand’s covid-19 deaths would have lived longer without the infection. The absence of the virus clearly would be unlikely to have saved the latest death who was hospitalized with a “serious non-covid illness” and then tested positive. Not without further supporting information, which if present, has been withheld from the public domain.

Since it is also now stated that not all deaths tested positive, it is hard to be certain that the absence of the virus would have saved other ‘apparent’ covid deaths. Indeed, according to a June 2020 OIA request, five of the 21 deaths (at the time) reported tested either negative or had not been tested. This is important, since covid-19 is not a disease with specific signs and symptoms, it is unclear that the absence of the virus would have saved these negative or untested cases.

This now leaves the covid deaths who tested positive. We are simply not given enough clinical information to know whether these lives would be saved without the virus on board. What we do know is that 16/22 deaths at June 2020 occurred in rest home residents, and that 8/14 deaths until April occurred in residents of a specialized dementia unit. We also know that the age distribution of these deaths is no different from background. This is further evidence that the absence of SARS-CoV-2 would not have altered the survival of these people.

In Italy, the place that scared many of us into thinking the worst about covid-19, it has now been proved that covid deaths were systematically exaggerated. The same is likely in the United States.

The one country that bucks the trend and uses a strict definition of a covid-19 death is Singapore. It also happens to have 29 deaths from 59,925 cases at the time of writing, with a case-fatality ratio of 0.05%, less than for seasonal influenza. It may be definitions, rather than lockdown protocols, that means the virus has had little effect there. Rather ironically, lockdown enthusiasts in New Zealand have championed Singapore for its societal restrictions, but they have not championed its use of covid-related definitions.

It looks increasingly as if covid-19 is a kind of chimera, largely created by our own modern fears.

This is bizarre, as Auckland moves into its next lockdown, estimated to cost our economy half a billion dollars per week, and as the queues in food banks are expected to grow, with the lives of our poorest communities most affected.

We must scrutinise not only whether our strategy hell bent on elimination of this virus is worthwhile, but whether it’s even based on reality.

Simon Thornley

22/2/2021

A New Zealand household case of the UK variant triggered another short lockdown in New Zealand. This will have prompted many of us to wonder “when will covid end?” The answer requires considering that we won’t eliminate the virus, and nor do we need to.

I was recently invited by a Canadian group to debate the motion that all countries should aim for “zero covid”. My opponent, health economist, Dr Stephen Duckett waxed lyrical about the virtues of the zero covid, since he was at liberty to attend the Australian Open tennis tournament.

He talked about the relative freedom of elimination compared to the UK and US which were enduring constant restrictions and high rates of infection. The podcast was freshly posted when Victoria went back into lockdown, as did the chances of Stephen seeing Novac Djokovic play live. I briefly felt self-satisfied that it wasn’t New Zealand, but within days it was. Auckland was back into level 3.

People may rightly hope that vaccines will be the answer. After two doses, the Pfizer vaccine was  claimed to reduce infection rates by 95%, with 8/21,720 cases in the vaccinated and 162/21,728 in the placebo. The rate at which these vaccines has been developed is a testament to human determination and skill.

However, we must also ask, why do most vaccines take ten years to develop and have we cut any corners? It is now clear that we simply do not know what the long-term benefits and safety profile of the vaccine will be. In South Africa, a trial of the once claimed 70% effective Oxford-AstraZeneca vaccine was rendered ineffective due to the emergence of the new variant with 19/748 in the vaccinated group infected, compared to 20/714 in the placebo.

Unanswered questions now are how effective the Pfizer vaccine is in the elderly, since in those aged 75 years or more there was only a total of five cases, with all occurring in the placebo group. While this is promising, it would be useful to have more definitive evidence about the elderly, since they are the target population for preventing fatalities from covid. There is little evidence on the ability of the vaccine to prevent their hospitalisation and death, which are surely the events we are hoping to prevent.

Since respiratory viruses frequently mutate, vaccine efficacy is unlikely to persist. We have seen this already with the Oxford vaccine, and the covid-19 end game remains unclear. As we’ve experienced, long periods without a community case are inevitably punctuated by community spread from the virus. As others have stated, it is a “tricky virus”. Indeed SARS-CoV-2 has been found in cats and dogs. The latest case indicates the limits of human understanding of transmission as we scratch our head about the source.

With all this uncertainty, unexpected good news has emerged, but you are unlikely to read about it in the newspaper. Hospital mortality in New York has dropped by a staggering 70%, comparing rates in March 2020 to August of the same year. While this suggests the introduction of new treatments, it is actually likely to be the opposite, in that less aggressive use of ventilators were likely to have improved survival in hard hit areas. Doctors in Toronto, like the public, were gripped with fear, initially quick to reach for the endotracheal tube, and have now realized the virus is not as deadly as they feared and become less trigger happy in reaching for the ventilator. The same pattern is replicated in both Italy and the UK. The finding of widespread covid-19 positive antibodies in Italy in September 2019 and a positive waste water test in Barcelona in March 2019, support the conclusion that it has been the response to the virus that has led to spikes in fatality.

What does this mean? We have all been gripped with fear from the virus. The government, as well as some doctors, have assumed that extreme caution will inevitably guide the best response. I believe this is well intentioned. However, this has led to preventable fatalities in some intensive care units, and to extreme public policy responses, that have prioritized the battle with this virus over all other health concerns.

Intensive care doctors had to learn that being cautious did not necessarily save lives, and instead led to harm. We need to learn the same about lockdowns and vaccines instead of naturally acquired immunity.

The concerns of livelihoods from small businesses, fiscal responsibility and mounting government debt have fallen into the background. Civil liberties and our way of life have faced the greatest restrictions since World War 2. Like doctors, our public policy makers need to dial back the fear, and contain the unintended consequences created by unnecessary, myopic, and destructive goals, such as the pursuit of national elimination of SARS-CoV-2.

Covid Plan B was ‘fact checked’ as ‘misleading’ for publishing on Facebook our article which used the existing conventional standard of statistical interpretation to find that a Danish study on mask wearing meant there was no significant benefit to wearing a mask against Covid19.

This so-called ‘fact check’ used a non-conventional approach which would mean that any study showing no significant effect of the studied intervention would mean the intervention does work.

This is clearly astounding. It reverses decades of scientific interpretation. It defies common-sense. But that is what ‘fact checking’ has become in the Covid19 era: a means of upholding the establishment policy position (using non-scientist media staffers).

It is not a means of checking facts. It is a means of denying them.

We outlined this deeply worrying development in an article in the British Medical Journal. Danish mask study: masks, media, fact checkers, and the interpretation of scientific evidence | The BMJ

Should we abandon convention altogether? If we did, we may eventually promote ineffective treatments. As an example, electrostimulation, laser therapy, and acupuncture are not generally thought to improve smoking cessation success, yet several promising pooled effects were calculated in a meta-analysis, although the majority were not“statistically significant.”

The tone of the“fact checking”piece that apparently supports mass masking as having a“small protective effect”over a conventional interpretation  as“misleading”turns usual scientific practice on its head. Pointingto observational evidence to contradict trial results is another subversion of usual epidemiological practice. While this may seem trivial, it is a subtle distortion of results and the politicisation of evidence in the covid-19 era.

Full PDF here: bmj.m4919.full