Covid-19

‘Contrarian’ academics oppose NZ lockdown

Analysis: A group of academics, led by health experts, have put forward a controversial plan to phase out New Zealand's stringent public health measures, but does their data stack up?

Simon Thornley thinks New Zealand has overreacted. The University of Auckland public health expert, who specialises in diet health and epidemiology, has been sounding the alarm for several weeks.

His first attempt, an opinion piece in Stuff in late March, triggered a backlash from other infectious diseases experts like Siouxsie Wiles, revealing a split within the scientific community over whether New Zealand's stringent lockdown was even necessary. At the time, a Newsroom analysis found Thornley relied on outdated statistics to make his argument.

In his March column, Thornley also pointed to Sweden as an example of a country that wasn't attempting to "squash a flea with a sledgehammer and bring the house down. I believe that other countries, such as Sweden, are steering a more sensible course through this turbulent time."

Since then, the country's death toll has risen rapidly, especially when compared to Scandinavian neighbours that chose to implement a lockdown.

Chart from corona.help.

Nonetheless, Thornley has now recruited a star-studded cast of high-profile academics to help him make the case for laxer measures. Chief on his wishlist is seeing the lockdown end nationwide next week and the country transition straight to alert Level 2.

"The way we stop the spread of an epidemic virus strain must be proportionate to the threat posed by the infection. The lockdown was appropriate when there was so little data, and when it seemed sensible to try to eliminate it or wait for a vaccine. But the data is now clear - this is not the disaster we feared and prepared for," Thornley said.

But is he right? Does the data stack up in his favour?

New Zealand's 'Plan B'

In a press release titled "expert group suggests way out of lockdown", Thornley introduced the team of academics pushing for New Zealand to take softer approach than the Government has signalled thus far.

Thornley is joined by fellow University of Auckland professors Gerhard Sundborn (a lecturer in population and Pacific health) and Ananish Chaudhuri (experimental economics), AUT's Grant Schofield (public health) and Victoria University of Wellington's Grant Morris (law) and Michael Jackson (biostatistics).

These academics believe the Government's response has been an overreaction based on flawed modelling. "One has to be quite sceptical of these models. For example, one model predicted 80,000 extra deaths in New Zealand. First of all, those deaths are deaths in people who would have a higher risk of dying during that year anyway," Thornley told Newsroom.

"We think that the response of the Government here has to be proportional to the risk posed by the virus and we don't think that a lockdown is a proportional response to the threat."

Together, the scholars have proposed New Zealand moves straight to alert Level 2 from next Thursday, when the earliest deadline for the lockdown is set to expire. The Government, meanwhile, has said it will make a decision on whether to extend the lockdown for the whole country or for certain regions on Monday. Any regions that do exit the lockdown will go to Level 3, which means some businesses will still be unable to open.

The details of the Level 3 restrictions will be released later this week, but Thornley wants to see a Level 2 where all schools and universities reopen, all leisure activities are permitted, domestic travel is permitted and nearly all employees return to working in offices. "Those over 60 and/or with underlying health conditions, and uncomfortable returning to work, could continue to work at home with support from their employer and government," the proposal states.

Self-isolation and social distancing will be maintained for vulnerable people - those over 60 or with underlying conditions - and high-risk communities like rest homes would still be more isolated, but the majority of people would return to living life as normal under Thornley's plan.

A handful of universal public health measures would remain in place: a ban on gatherings of 100 or more people, border entry restricted for the "near-future", and contact tracing and testing capabilities would remain active.

Thornley also wants to see widespread testing of the population for antibodies - immunity to the virus. He believes, after reviewing a preliminary study of the German town of Gangelt, where 80 percent of the population was tested and 14 percent found to have antibodies, that a sizeable chunk of New Zealanders may have had Covid-19 and not known it.

A difference of goals and values

In the end, Souxsie Wiles says her disagreement with Thornley can only be explained in one way: they have fundamentally different values.

Even if the virus just killed people who might have been likely to die of something else, Wiles says it would still be worth fighting. "I'm just opposed to the very fundamental values base that they're coming from, around how it's okay to let people die of this because they would die anyway, or something? My understanding is this is one of their core arguments for having a different plan," she said.

"This comes down to a values thing and what you're willing to sacrifice for that."

Thornley says this is a fair framing. "In terms of Siouxsie's comments, yes I am concerned about elderly people but I think this is a balanced approach to developing policy around the virus. We can't shut down the country. We have to make an effort, as much as we can, to protect people both in hospital and in rest homes," he said.

Similarly, University of Otago epidemiologist Michael Baker says his opposition to Thornley's conclusions lies in the fact they are seeking different goals. Baker wants to eliminate the virus in New Zealand - and that is the Government's stated policy. Meanwhile, Thornley doesn't think that's feasible.

"I think Michael believes we can deal with this virus a bit like we deal with measles, where most cases are symptomatic and we can identify them all and we can eliminate the virus from New Zealand. I don't think that the virus behaves in this way - that there's a lot of asymptomatic infection around the community. It would be like hunting for a needle in a haystack," he said.

Baker told Newsroom: "He doesn't think we should be even trying to eliminate this infection. Whatever they say about the [alert] levels seems to me to be pretty meaningless if they've got a completely different goal in mind.

"That's what I don't understand. I think Simon and some of the other people involved are taking up what I call a contrarian view that I don't think is backed by evidence. And also the evidence we can all see in front of us globally. Everyone I speak to internationally would dearly love to be in the position New Zealand has now got itself into, by acting decisively, where we have choices.

"Like most of the Western world, we are enduring very tough lockdown conditions which, of course, no one wants. But, as we have said repeatedly, this is the least bad strategy because it gives us an exit strategy and that exit strategy seems tantalisingly close: that we can transition to a Covid-free New Zealand in the foreseeable future."

"I'm not hearing an appealing alternative from Simon and Grant Schofield. Their alternative seems to be either the 'let-it-rip' herd immunity approach which has failed dismally overseas or a suppression strategy, which is that you endure either continuous or intermittent lockdown for the foreseeable future to avoid saturating your health system," he said.

The Australian example

Ask Thornley why he thinks New Zealand can get away with lighter measures when other countries have tried and failed to do so and he'll point to his one, constant refrain: Australia did it.

"I think that Australia really provides the strongest evidence in terms of comparisons to New Zealand. They're much more similar to us in a whole range of respects: particularly population density and structure of their health system. They have weathered the storm very well with a much more relaxed form of lockdown," he told Newsroom.

This is largely true. Although Australia has phased in stricter measures in recent weeks, its lockdown is still far less stringent than New Zealand's. The virus also spread faster there, infecting more than 6,000 people and killing 61. But now our neighbour across the Tasman appears to have broken the back of the outbreak, with a decline in active case numbers nearly every day since April 5.

Epidemiologist Sir David Skegg told the Epidemic Response Select Committee on Tuesday he finds Australia "a bit of an enigma, actually, because it's certainly true that their number of cases notified, on a population basis, is very similar to ours. But actually that measure is probably the least reliable because it depends so much on testing."

"If you look at the harder endpoints in terms of the occurrence of the disease, they have a lot more deaths than we do. It's difficult to make comparisons there because fortunately, we have a small number, and you get into a small number problem. But if you look at hospitalisations - I just looked yesterday - Australia has got 378 people in hospital with Covid-19. And we have 15."

Even taking into account the population difference, Australia has five times as many hospitalised Covid-19 cases per capita as New Zealand does.

Skegg also said while Australia has imposed less stringent measures, it is planning to be there for six months. New Zealand, meanwhile, is attempting to eliminate the virus in New Zealand over the course of a matter of weeks through stricter but shorter-lived measures.

'Cherry-picking' data

Siousxie Wiles says pointing to Australia but ignoring cases like Sweden shows Thornley is cherry-picking his data. "They used Sweden as their example last time, so it's a little bit like they're looking for the countries that support their argument rather than using the data," she said.

"I think when you pick one, you're cherry-picking. That was what they did when he wrote his last piece, he cherry-picked. And then when those examples didn't quite work out, he's cherry-picking some new ones."

In response, Thornley says: "There is a lot of uncertainty here. But we have to try and negotiate a strategy through this. We have to choose what we think is the best data, what is the best comparison. And I've given you the reasons why I think that is the best comparison. There's a lot of different stories you can attend to on this subject, but as an epidemiologist, I want to try and choose what I feel is the best data to inform our strategy"

Thornley's argument, that Australia is a suitable match due to similar population densities, doesn't quite add up. New Zealand's population density is six times that of Australia and is much closer to that of Sweden, Norway or Finland.

When examining only the density of CBDs, Auckland has a population density nearly three times that of Melbourne, four times that of Sydney and Perth, and nine times that of Brisbane.

Meanwhile, it has nearly the same population density as Gothenburg, Sweden's second largest city and the city with the second-highest number of Covid-19 cases in the Scandinavian country. The outbreak there is bad enough that a temporary field hospital has been constructed and ice skating rinks have been rented to store coffins.

But does population density even figure into the severity of a given outbreak? Financial Times analysis found only a weak correlation between countries with high rates of urbanisation and the death toll in those countries. A much stronger correlation was observed between the speed at which a country locked down and the number of deaths it then experienced - countries that entered lockdown when the daily death toll was below 1 were more likely to limit the toll to a peak of around 30 deaths a day.

None of this fazes Thornley, who continues to see Australia as the best - and nearly only - example worth considering. When asked if he could point to other countries with lax measures that have enjoyed success he mentioned East Asian countries that have received considerable attention within the public health community.

"Singapore, Hong Kong and South Korea have had much more relaxed social distancing restrictions than New Zealand and they've generally done very well," he said.

However, Singapore is now entering lockdown and Hong Kong is anticipating a third wave of infection that could force it into lockdown. South Korea succeeded through the use of a vast testing, contact tracing and case isolation regime. This is something New Zealand needs in order to exit lockdown, according to modelling from Te Pūnaha Matatini, but experts are concerned we aren't there yet.

In front of Tuesday's select committee, Skegg said he was worried New Zealand wasn't ready for rapid case isolation.

"As soon as the lockdown is lifted, the epidemic will take off again unless we have the other measures in place. Now those other measures are widespread testing, and I think we've made a lot of progress in that area. But also effective systems for very rapid tracing of contacts, and I'm not confident that we've achieved that yet," he said.

Director-General of Health Ashley Bloomfield said New Zealand is able to trace the contacts of about 100 cases per day.

How bad is it, really?

The corollary to Thornley's first argument, that measures this stringent aren't needed to fight the virus, is his second argument: the virus isn't as bad as we're making it out to be.

Thornley attempts to establish this premise in a number of ways. First, he insists the fatality rate of the virus has been drastically overestimated by pointing to the 2009 Swine Flu outbreak and the Gangelt study. A study the year after the H1N1 pandemic found far more people had been infected than previously thought, meaning the percentage of people with the virus who were killed by it was substantially lowered.

If Covid-19 is also infecting far more people than expected and they are displaying mild or no symptoms, it might not be as dangerous as it seems, Thornley argues.

Mortality estimates for Covid-19 have fluctuated wildly and there are few closed populations - where an entire population has been tested - to use for comparison. The Gangelt study, which provides an example of near-total testing of a population, found a fatality rate of 0.37 percent - much lower than other estimates.

However, other closed populations cast doubt on the accuracy of this estimate. The Diamond Princess cruise ship saw 12 deaths out of 712 confirmed cases - a case fatality rate of 1.68 percent.

"The issue is: what is the overall risk of this virus to our population? Yes, it is more important than seasonal flu, but it's not that much more important," Thornley told Newsroom.

He also relied on a figure stating that just 12 percent of Covid-19-related deaths in Italy were due to the disease alone, with no underlying conditions. It is unclear where Thornley sourced this figure from, although an identical claim can be found in a March 23 article in The Telegraph.

Wiles, however, says the death rate could also be underestimated. She points to examples in the UK and Italy where patients who haven't been tested for the virus but obviously had it are not being marked as Covid-19 deaths.

"Just because they're saying that 12 percent of deaths are caused by Covid-19 [alone], how is that defined? So I know that lots of countries are not reporting deaths even though they might have been Covid-19 because the person hadn't tested positive, but they're not testing dead people," she said.

Then there's the knock-on impact of a severe outbreak.

"In those countries with overwhelmed health systems, there are people who die, and while they haven't died of Covid-19, it's not fair to say that they might have died anyway. Their deaths then are related to Covid-19. Using that '12 percent of deaths from Covid-19' I think is extremely misleading," Wiles said.

'They were going to die anyway'

Thornley's second reason for saying the virus isn't so bad is one that has been made in the past: because many of the people dying of Covid-19 are older and have underlying conditions, they may well have been killed by something else anyway.

Radio personality Mike Hosking said as much after a chat with Thornley in March. "They were going to die anyway," he said.

"Something was going to get them, it just happens to be this. Or maybe it wasn't. Or maybe this exacerbates it. Or maybe this complicates it."

As evidence, Thornley says we haven't seen an uptick in overall mortality in many countries. In other words, even if deaths are being attributed to Covid-19, the total number of people dying is the same as in previous years.

"One of the leading statisticians in the UK has characterised it by saying that the risk of dying from Covid-19 is about the same as your annual risk of dying in that year anyway," he said. "So that puts it in perspective and I think there has been a loss of perspective about the severity of Covid-19."

However, a review of the evidence doesn't bear this out.

The below chart from a project that monitors excess mortality in Europe shows a spike in mortality throughout much of the continent. It is also two weeks old, dating to a point when there were just 785,000 global cases of the virus, when today there are 2 million.

When presented with this data, Thornley said Germany helps prove his point. Only parts of Germany are covered by the project but they haven't registered a major uptick in mortality.

"There's varying data overseas. I've been looking at overall mortality rates, which you can see in Europe, there's a good summary of those for each country. In some countries, yes, there's increased rates of mortality overall, but in other countries that have been heavily affected, such as Germany, there's virtually no change in overall mortality," he said.

"It may be that that increase in mortality is what we call a 'harvesting effect', where people who are likely to die in the near future all die at one point and there's a little spike in mortality. So it certainly hasn't been as dramatic as I would have expected looking at those overall mortality figures."

But Germany's low death rate - 3,124 to France's 14,967, when the two have a similar number of cases - is, like those in Singapore and South Korea, attributable to its robust testing and contact tracing system. Famously, German authorities traced the first case of community transmission to a specific salt shaker in a car parts factory. Moreover, Germany has one of the strictest lockdowns in the world - hardly an example bolstering Thornley's argument for more relaxed measures.

Meanwhile, other European countries that came late to the lockdown party have seen jumps in mortality. Belgium, France, Italy, the Netherlands, Spain, Switzerland and England have all experienced a greater deviation from average mortality in recent weeks than at any other time in the past five years, according to the data from two weeks ago. By now, that is likely to have worsened further.

Besides, Wiles says, this discussion around mortality rates is missing the forest for the trees. "I just still can't get over the fact that countries are digging mass graves. What about that is normal?" she said.

"Saying that flattening the curve to stretch the deaths out and everything will be okay is based on two premises. It's okay for those people to die - that's an acceptable risk - and that it's just going to be the vulnerable. It's also just a judgment call. Why should we be okay with vulnerable people dying?

"There's a great line in one of the Shrek movies: 'Some of you may die, but that is a sacrifice I'm willing to make'. It feels a little like that."

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