Otago has the country's highest rate of grommet insertion - a procedure in the sights of a Government health committee tasked with finding savings in the health sector.
The National Health Committee has suggested possible annual savings of $4.4 million through inserting fewer grommets, which are tiny ventilation tubes inserted into the eardrum, used to treat glue ear. Since it was revealed this month, the committee has emphasised its proposal is at a very early stage.
Dunedin Hospital ear, nose, and throat specialist Martyn Fields said it was unclear why Otago had the highest grommet rate, and Southland the third highest. Ministry of Health data shows Otago's standardised discharge ratio in 2010-11 of 1.84 for grommet surgery was the country's highest.
North Island boards did fewer procedures than South Island boards, with Hawkes Bay doing the least, with a 0.59 standardised discharge ratio. Mr Fields said glue ear was not over-treated in the South.
''I send back at least half of the children I see [for ear infections], as they do not meet departmental guidelines to recommend surgery.
''For every child who gets referred in with ear infection problems, probably less than a third end up with grommets.
''We're not offering surgery to every child who walks through the door - we do know that there's a finite amount of money, and try and target those most in need,'' Mr Fields said.
Reasons for more surgery in the South included its cooler climate, efforts by local specialists to educate GPs about glue ear, and lower uptake of private healthcare.
Mr Fields believed publicity about the possible cost-cutting had been a ''little bit misleading'', as the work was preliminary.
However, he would be concerned if the Government introduced a nationwide cap on the procedure.
He would not like to see New Zealand follow Britain in making clinicians follow rigid box-ticking rules.
''Just putting a cap on the number of children we can do, as opposed to the ones that need it, then they're in for a big public backlash.
''It's bad enough that children are waiting four to six months to have their operation in Dunedin at the moment.''
He would be happy to see more consistency in national treatment rates.
Grommet surgery in areas of expected high need, such as Counties Manukau, was relatively low, which probably showed parents there were not adequately accessing medical care, Mr Fields said.
It cost $1800 to $2000 to have grommets inserted privately, he said. In a letter to Royal Australasian College of Surgeons chairman Scott Stevenson, National Health Committee chairwoman Anne Kolbe said the committee would formally engage with the New Zealand Society of Otolaryngology, Head and Neck Surgery before making formal recommendations about grommets.
The committee's task of finding health savings was not straightforward.
''Other [countries'] use of lists of ineffective or low-value interventions, while indicating significant savings [which we need to understand], has difficulties from our perspective.
''They are difficult to convert into the New Zealand context and they also tend to focus on procedurally-based specialties because of the ease of data collection,'' the letter said.
Dunedin South MP and Labour disability spokeswoman Clare Curran said housing quality, the climate, and lower incomes were likely reasons for the South's high grommet surgery rate.
Cutting grommet surgery would lead to significant increases in learning and behavioural problems, she believed.
