Speed was a sign hearing screener faked tests
A screener who was faking hearing test results for babies at Hutt Hospital was exposed by the speed of her work.
The woman denied any wrongdoing, despite data suggesting otherwise, documents obtained under the Official Information Act show.
She later resigned.
A review found her hearing tests were being performed in just 25-30 seconds, compared with an average of more than a minute and an upper range of up to eight minutes.
Normal rescreening rates - when new appointments have to be made because a test is unclear - should have been between 8 and 15 per cent, but the woman's rate dropped to about 1.5 per cent.
An auditor described the results as "concerning and most likely impossible".
The worker had tested her own ears to falsify results as she screened newborn babies for hearing loss.
More than 900 babies screened at Hutt Hospital had to be recalled for retesting as a result, with 176 found to have been screened incorrectly.
They included Addison Blundell, whose total hearing loss was not picked up until she was 10 months old. Now 15 months, she recently received a double cochlear implant.
A Health Ministry investigation this year found that eight screeners, of about 108 nationwide, had carried out incorrect tests, either by screening the same ear of a baby twice, or by screening their own ears.
The newly obtained documents show the Hutt Hospital screener was asked to explain, but: "We have been unable to hear directly from the hearing screener her reasons or rationale behind her inaccurate screening practice."
The woman said she had been working hard, and denied providing false results. Sections covering her identity, mental and emotional state were withheld from the released documents.
One possible explanation offered in the report was that the Hutt Valley District Health Board had a high volume of mothers who were discharged from hospital soon after delivery.
"Rapid discharges put stress on hearing screeners, as families want the test done as soon as possible so they can leave the hospital."
The tester's incorrect screening began in May 2011, seven months after she started work.
Screeners do not need prior qualifications or experience, and need only to pass a two-week training course at the University of Canterbury.
The screener was required to perform a daily test on her own ears, the report said.
"Knowing she could obtain a pass result easily in her own ear may have 'planted the seed' for a method of incorrect screening."
Hutt Valley District Health Board chief executive Graham Dyer said steps were in place that should quickly detect similar failings. These included weekly monitoring of screening data.
The ministry's final report on its investigation had 21 recommendations, including a national database for quality monitoring, professional development and support for screeners.
THE STORY SO FAR
July 20, 2012: Review of Hutt Hospital's screening data, after a report of inaccurate testing in Britain.
July 23: Concerns raised over data from one tester. Screener denies any wrongdoing. She later resigns.
July - August: Hearing data evaluated.
August 8: Health Board and National Screening Unit notified.
August 20: Rescreening of more than 900 babies begins. 176 identified as incorrectly tested.
Late 2012: Ministry of Health investigation launched, after irregularities in its national newborn screening programme, which began in 2007.
February 2013: Investigation finds eight screeners, out of a workforce of about 108, had not followed protocol. Irregularities were detected at six district health boards: Auckland, Lakes, Bay of Plenty, Waitemata, Canterbury and Hutt Valley.
The Dominion Post