Prime Minister Jacinda Ardern. Photo / Mark Mitchell
COMMENT:
Close to a third of the population is back in lockdown after confirmation this week of 17 new Covid-19 cases, all of which have spread in the community.
Outside Auckland, the country is on standby under milder social distancing rules. And whether the current rules will be extended, toughenedor relaxed when Cabinet meets to decide the matter on Friday remains anybody's guess.
But the need to understand the Government's calculus is looming larger by the day.
As restrictions once again suspend lives, shutter businesses and fan fear, we need to ask the question, both of ourselves and of our political leaders: how will we know when the price of lockdown is too high to countenance? And when will we know that the quest for absolute zero is no longer worth the suspension of normal life, or even when it is no longer worth the tough restrictions at the border?
After the move to level 4 lockdown in March, the Government released a series of models that produced death rates from Covid-19 that looked unconscionably high.
One scenario modelled deaths at 27,600. Two more optimistic scenarios produced a death toll of 8500 and 14,400 respectively. Without lockdown, those models suggested a virus deadly to perhaps 1 per cent of those infected would tear through the population and in all likelihood overwhelm the healthcare system.
It was a price, Prime Minister Jacinda Ardern said, she was not prepared to entertain. But we are now nearly five months on from that bleak March decision. And the numbers on which the Prime Minister relied look very wrong.
For one thing, it is becoming clear Covid-19 is not as deadly as previously feared. Early in the year, death in 1 per cent of cases was assumed. The US Centres for Disease Control and Prevention now roughly estimate an IFR (Infection Fatality Rate) at about 0.65. The World Health Organisation says estimates of the IFR are "converging at approximately 0.5 per cent to 1 per cent".
One factor is that, early on (and perhaps still) infection was underestimated, exaggerating the deadliness of the disease.
Another factor is that treatment is improving. Doctors were initially dumbfounded by the novel coronavirus. They now have better hospital protocols such as prone positioning and are prescribing drugs like the steroid dexamethasone in high-risk cases. Hospital mortality is declining in countries including the US, Italy and the UK.
Sweden remains a pertinent comparator since it never locked down, though it has instituted a series of largely voluntary distancing measures. After an April spike, the country's deaths have dwindled to a handful per day, though they sit cumulatively around 5700 according to Johns Hopkins University (New Zealand has roughly half Sweden's population).
The Government needs to transparently revisit the old figures on which it based initial lockdown decision-making. It also needs to weigh the evolving costs and benefits of its current pandemic plan, which is to achieve zero cases of the virus beyond managed isolation at the border. Its decisions need not be dictated by cost benefit determinations, but its judgement must be informed by those calculations. Anything less is to simply follow a gut feeling.
Cost benefit analysis has already been deployed by the Productivity Commission to examine the five day extension to level 4 lockdown in April. By the Commission's yardstick, the overtime wasn't worth it: the analysis found a net cost to the country of $741m.
Importantly, the analysis employed Quality Adjusted Life Years (QALYs) to weigh the health benefits of the lockdown extension. QALYs provide a measure of both life years and quality of life and are commonly used in government to evaluate health spending (Treasury values one QALY at $33,000).
The use of QALYs, rather than a raw death rate, is especially important in understanding the cost of Covid, since the disease produces a death and hospitalisation rate that is heavily skewed to the very old and those who are already infirm. Weighing life years rather than whole lives lost adds a critical nuance.
The value of normalcy, both for the economy and more broadly for people's lives, is clearly enormous. But so too is the cost of lockdowns. As, indeed, is the cost of an all but closed border under level 1. And the longer the pandemic drags on in the wider world, the less tenable New Zealand's isolation strategy becomes.
It is clear that estimates of the health cost of Covid-19 have diminished since the start of the pandemic. There will be a time when the best option is to ease border restrictions, abandon lockdowns, and let our health system, including tracking and tracing and testing, do the heavy lifting. We need credible analysis to help us know if that time is now.