NZ bucked virus trend, study shows
WELLINGTON: The first two years of the Covid pandemic undid earlier success in increasing life expectancy, except for in a handful of countries — New Zealand among them.
Global life expectancy declined by 1.6 years between 2019 and 2021, reversing the longstanding trend of life expectancy improvement, according to the latest analysis of the Global Burden of Disease study, known as the largest and most comprehensive effort to quantify health loss across places and time.
Coordinated by researchers at the Institute for Health Metrics and Evaluation at the University of Washington and published in The Lancet on March 11, the analysis tracked trends in excess mortality and life expectancy within and between more than 200 countries and territories.
But for seven of those — New Zealand, Taiwan, Mongolia, Japan, Iceland, Antigua and Barbuda and Barbados — the allage excess mortality rate for 2020 and 2021 combined was negative.
That meant the locations experienced fewer deaths during the first two years of the pandemic than expected based on past trends.
In 2020, 20 countries and territories had negative excess mortality, while in 2021, only New Zealand and Barbados had negative excess mortality.
‘‘For adults worldwide, the Covid pandemic has had a more profound impact than any event seen in half a century, including conflicts and natural disasters,’’ author Dr Austin Schumacher, an assistant professor of health metrics sciences at the institute, said in a statement.
The paper said the pandemic killed nearly 16 million people worldwide in 2020 and 2021, accounting for about 12% of deaths from all causes.
Between 1950 and 2021, global life expectancy at birth increased by 22.7 years, from 49 years to 71.7. But in the period between 2019 and 2021, it declined by 1.6 years.
During the same period, longterm trends of decreasing mortality were superseded by marked increases in mortality rates in age groups older than 15 (22% for men and 17% for women).
However, mortality in children under 5 years was largely unaffected by the pandemic and continued to decrease (by 7%).
Excess mortality due to the pandemic was defined as the ‘‘net difference between the number of deaths that occurred between 2020 and 2021 and the number of deaths that would be expected over the same period based on previous trends in allcause mortality’’ — in other words, the total number of deaths minus the number of expected deaths based on historical trends.
Globally comparable measures of excess mortality due to the pandemic showed substantial variation in the burden experienced by different countries and territories, the authors wrote.
‘‘These findings provide further evidence supporting the effectiveness of the elimination strategy for minimising mortality from the pandemic,’’ University of Otago epidemiologist Prof Michael Baker told RNZ.
It was not until 2022, after the government had relaxed pandemic controls, that the country had its first major outbreak, fuelled by the highly transmissible Omicron variant.
In 2022, deaths in New Zealand were up 10.4% on the previous year — the biggest annual increase since 1918 (following the influenza pandemic).
In total, nearly 6000 New Zealanders have died with Covid, according to the latest Health New Zealand Te Whatu Ora data.
But compared with other nations, New Zealand is said to have got off lightly.
‘‘[The paper] reinforces other evidence that New Zealand’s response was extremely effective at minimising mortality during the pandemic,’’ Prof Baker said.
The country’s Covid mortality rates were still ‘‘among the lowest in the world’’.
‘‘But it’s a point in time, so it’s limited in what it’s telling us about our current experience.
‘‘We’re still in a prolonged pandemic mainly because the virus keeps changing.
‘‘We’ll have to wait at least another year for the next update, which will include the period we were heavily exposed to the virus.’’