Analysis: Data provided by the Ministry of Health shows daily scan numbers spike whenever alert levels are raised but quickly subside when normality returns, Marc Daalder reports

As New Zealand yo-yos in and out of lockdown, New Zealanders are yo-yoing in and out of scanning QR codes.

The latest data from the Ministry of Health further reinforces a trend where scan counts spike when alert levels are raised but quickly drop back down once the country returns to Level 1. It also underscores calls from public health experts and some politicians for scanning QR codes (or signing into paper contact tracing sheets) to be made compulsory.

The NZ COVID Tracer app is meant to speed up contact tracing, allowing officials to quickly ringfence outbreaks and avert the need to escalate alert levels. When a woman who left managed isolation and travelled around Northland for a week tested positive for Covid-19, public health officials quickly provided a comprehensive list of her whereabouts because she had been “assiduous” in her use of the app.

Compare that to cases in the Valentine’s Day cluster, where new contacts are still being uncovered by officials every day, and the usefulness of the tool becomes clear. The app is also privacy-first, which means that location and contact data is stored only on the user’s device and can only be sent to the Ministry of Health with the user’s permission.

Usage still low

We know that more people could be using the app because, in the past, more people have. As Auckland entered Level 2.5 after two-and-a-half weeks in lockdown last August, daily scan counts spiked to a peak of more than 2.5 million in one 24-hour period.

As the chart below shows, which uses a rolling average to smooth out the difference between weekends and weekdays, daily scans hadn’t risen to even half of the mid-September peak before the latest lockdown.

In other words, we know that there are many people not scanning as much as they could be, as more than a million scans short of the mid-September peak.

“We’re still well away from targets of what we think would actually give us confidence that, in the event of any outbreak, we’d be able to find the contacts that we need,” Andrew Chen, a research fellow and digital policy expert at the University of Auckland’s Koi Tū – Centre for Informed Futures, told Newsroom.

Almost without exception, scan counts plateaued or dropped after September until a Covid-19 scare, at which point they spiked for a week or so and then dropped once again. The base level scans dropped to was generally higher than the previous one, but very little of the increase was conserved. Scans only rose with Covid-19 scares – the port worker case after the election, a mystery case in Auckland, the Northland MIQ breach and then the Valentine’s Day cluster.

It seems clear that at least some people know they should be scanning more. Each Covid-19 scare sees an immediate spike in manual entries, indicating people are logging the places they visited recently where they hadn’t scanned.

“Most people would say they get it, this is something that they should do. In the same way that people know that wearing a face mask is something they should do. And then when the rules change and now you have to wear face masks on public transport, most people are doing it,” he said.

“When there’s an alert level change, they go, ‘Oh, I probably should have been keeping better records. Let’s go back and try to get them all back in now.’”

Chen added that the level of increase suggests people are just updating their movements over the previous few days, not the past week or two.

The one form of app use that doesn’t decline after new outbreaks is Bluetooth tracing. Because this is a passive form of tracing, in which people enable it in their app and then don’t have to do anything else, the number of devices with Bluetooth activated rises with each new Covid-19 scare and then plateaus. That’s still not as desirable as consistent increases but it’s better than a decrease, Chen said.


The lack of scanning has led to calls for the act to be made compulsory.

In January, the ACT Party called for mandatory scanning, with leader David Seymour saying, “You can bet that many of those using Bluetooth are also the ones scanning in, which means only a fraction of New Zealanders are using any electronic means of rapidly tracking and tracing a Covid-19 outbreak. Many New Zealanders are understandably hesitant about government compulsion, but sometimes, as in this case, not scanning in or using Bluetooth tracking is simply too dangerous to remain optional.”

Public health experts have also called for more limited scanning (or manual sign-in) mandates. University of Otago epidemiologist Michael Baker said scanning should be required at high-risk locations – gyms, nightclubs, churches and some restaurants. In other words, indoor spaces where talking, singing or shouting are likely to occur and where it is difficult to social distance. Anything that could turn into a super-spreader event should have a mandatory scanning rule.

“We want to know about super-spreading events. We know what they are – they’re indoor environments where people get quite close together and talk, laugh loudly and even sing,” he said.

Likewise, Philip Hill, a contact tracing expert at the University of Otago, said people entering high-risk locations and attending indoor gatherings should be required to scan (or sign in manually).

“I can see no reason why people who are running a gathering – an indoor gathering in particular – of any size should not be required to make sure that their attendees are scanning QR codes,” he said.

Digital inclusion

Chen says that compulsion, if handled right, could increase uptake. However, there are a few considerations before leaping into it.

On the one hand, he said, there are concerns that Apple and Google, who developed the Bluetooth tracing protocol in the app, might oppose an effort to make scanning mandatory. That could lead to Bluetooth tracing being stripped from the app. However, while Apple and Google had previously opposed any efforts to combined QR scanning and Bluetooth in the same app, when the United Kingdom added scanning to their programme the tech giants acquiesced.

Then there are the people who may not be able to scan.

“The next low-hanging fruit of people who we need to be targeting are the people who want to be participating but can’t,” Chen said. “That could be for any number of reasons, but the most significant ones seem to be language barriers and not having a compatible device or not having a device at all. I think that is probably the next step that the Government needs to take.

“There are substantial numbers of people who cannot participate at the moment. And if they were to introduce mandatory scanning, I would say you would have to introduce a bunch of digital inclusion policies at the same time. Otherwise, you will have a significant backlash. It will create a lot of confusion and anxiety for people. Particularly for those who can’t, but also people who know people who can’t. You go one order of magnitude out and suddenly it’s a decent proportion of the population.”

While this could be avoided by mandating scanning QR codes or signing in manually, Chen said the Government should see this as an opportunity to address digital exclusion. Giving people access to smartphones could not only increase uptake of digital contact tracing, but also put people in contact with public health guidelines and other government services, like WINZ.

The cheapest smartphones sold by Spark and Vodafone are compatible with the app, Chen said. The Government could issue vouchers for the price of those phones to people without access to a compatible device, he suggested.

“If the Government genuinely believes that use of the app is a critical tool in our response to Covid-19, then they should invest more in it.

Marc Daalder is a senior political reporter based in Wellington who covers climate change, health, energy and violent extremism. Twitter/Bluesky: @marcdaalder

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