A doctor who missed an x-ray result that could have helped diagnose a woman's terminal cancer three years earlier says he was tired and may not have actually read the report.

The patient, a woman in her 60s, showed up to Waikato Hospital with stomach pain and nausea in March 2017 and was seen by a doctor at the emergency department.

A set of x-rays was ordered and the technician reviewing the pictures noticed an unusual mass on one of the woman's lungs.

When the technician sent their notes to the doctor nearly two weeks later the doctor "overlooked" the vital comments.

Three years later when the woman showed up to the same emergency department, she underwent further x-rays and was found to have lung cancer.

Health and Disability Commissioner Morag McDowell today said in a decision released today that the woman, who has since died, was failed by a lack of communication and by a delays in reading the x-ray results.

The emergency department doctor who ordered the x-rays of the woman's chest told the commissioner he overlooked the technician's comments that a possible mass had been detected on the woman's lung.

"Had I seen this comment, I would have made a specific comment and additional note on the discharge form regarding the plan for follow up, which would have included further investigation with a chest CT scan.

"Regrettably I did not do this, which meant that the patient was not advised of the presence of the mass and further investigations were not undertaken."

He went on to say that he believes his oversight was caused by fatigue and he may have accidentally clicked the "acknowledge" button on the report but did not actually read it.

The doctor said that at the time of the patient's admission staff were under instruction to clear a backlog of unacknowledged results and he did this at the end of his shift when he was tired.

The results of the woman's x-ray were also sent to her general practitioner, however a new doctor to the practice thought it was the hospital's responsibility to review the results as they had ordered the scan.

In January 2020 the woman presented to Waikato Hospital's emergency department again with a suspected stroke and it was then that another doctor reviewed her x-ray results from three years earlier.

A chest x-ray and CT scan were ordered as well as a tissue sample which confirmed that the woman had terminal lung cancer.

The woman's daughter told the commissioner that the diagnosis failure had had a devastating effect on the lives of her mother and family.

"We are very sad that the outcomes may have been different with better systems and checks in place in 2017."

She also asked that system improvements be implemented at Waikato District Health Board so that other people do not suffer the same consequences as her mother.

The commissioner recommended the emergency department doctor apologise to the woman's family and undertake a full audit of radiology reports that had been marked as acknowledged by him.

She also ordered that a third party audit those results to ensure that a similar situation does not occur again.

The doctor told the commissioner he now dedicates time during his day shifts when he is not fatigued to review and acknowledge test results.

Among McDowell's list of findings was that the timeframe of 11 days to receive radiology results was too-long and that the hospital and the woman's medical practice needed to have clearer systems in place for communicating.

- Jeremy Wilkinson, Open Justice