New research is shedding light on the impact of COVID-19 Alert Levels on injury-related hospital admissions across the Midland region and how people were injured during lockdown.

The Midland region is made up of Bay of Plenty, Tairawhiti, Taranaki, Lakes and Waikato District Health Boards which together cover a population of approximately 985,285 people.

The study by the Midland Trauma System - MTS, published in the New Zealand Medical Journal yesterday, shows a marked decrease in admissions during Alert Levels 4 and 3 last year, but found it was short-lived as the country moved to levels 2 and 1.

It also revealed some significant fluctuations in the types of injuries presented to emergency departments at Midland hospitals.

The research team says the data from the study will help inform planning around demand and healthcare access for similar scenarios in the future.

The research covered the period of February 15 to July 11, 2020 and compared it to the average number of admissions during the same period between 2017 and 2019.

That timeframe covers pre-lockdown, the week of lockdown and the movement through all four alert levels. However, the research team focused on Alert Levels 4, 3, and 2 to try and exclude dramatic changes in behaviours as the region prepared to move into Level 4 restrictions and Level 1 which had practically no community restrictions.

Data showed a 36.7 per cent drop in admission rates during Alert Level 4, while a 16 per cent drop was seen during Alert Level 3.

In contrast, admissions rose by 17.8 per cent in the pre-lockdown period of February 15 to March 18. The reduction in patients during Alert Levels 4 and 3 was brief, with admissions rising by 6.5 per cent in level 2 and 13.8 per cent in the first month of Alert Level 1.

The hospitals saw an overall decrease in admission volumes of 18.3 per cent across Alert Levels 4, 3, and 2.

Fewer men were admitted in 2020 compared with the previous years - a drop of 21.9 per cent, and while there was a drop in presentations across all ages, the most significant reductions were in the 5-14, 15-24 and 65-74 groups.

The ways people were injured also changed. There was a 63 per cent drop in pedestrian injuries, while cycling and motorbike-related admissions rose 11.9 per cent and 2.2 per cent respectively.

The researchers suggest the increase could have been a result of more new and returning cyclists taking up the hobby during the lockdown while there were fewer cars on the road.

Road traffic crashes typically account for the second highest number of injuries across the Midlands after falls.

Admissions of people injured in vehicle incidents dropped by 35.8 per cent, coinciding with the significant restrictions on movement during Alert Levels 4 and 3. However, compared to the previous three years this is not considered a significant proportional change.

Perhaps unsurprisingly, there was an increase in injuries around the home with admissions up 28.3 per cent. Injuries on footpaths increased by 37.9 per cent.

There was a significant drop in injuries occurring at schools (down 75 per cent), sports areas (down 79 per cent) and in and on the water (down 71.4 per cent).

The researchers say public health messages to essential workers to stay safe and keep pressure off the health system appear to have paid off. These messages were also relayed to the farming community which continued operating throughout lockdown.

Farm-related injuries increased by 1.7 per cent during the research period.

"We were interested to see only a small increase in all injuries requiring hospital-level care occurring on farms, despite farmers and farm workers continuing their daily work-related activities during national-level restrictions," the researchers say.

Alert Level 2 and the first month of level 1 saw a spike in admissions compared to the previous three years.

This rebound coincided with a campaign by DHBs to catch up on healthcare procedures such as elective surgeries which were temporarily suspended during lockdown.

The report says the "potential resource squeeze" as a result of the rebound in admissions must be taken into account when planning for future lockdown scenarios.

This research paper expands on an earlier report by the MTS in April 2020 which looked at the change in the number and kinds of injuries at Waikato Hospital during the first two weeks of Alert Level 4.