Keeping the full results of the bowel cancer screening programme from patients could be illegal, a group of bowel cancer experts is warning.
The Health Ministry is defending its decision not to give patients in the bowel cancer screening programme their full test results, saying it could just confuse them, after the group led by Brian Cox from Otago University said they were concerned.
Dr Cox, a preventive and social medicine researcher, said participants were not told if they have blood in their stool. A significant amount of blood may be detected in a test, but the result would still be negative.
"National bowel screening programme reports the result of blood in the faeces or stool as positive or negative according to a cutoff they use."
"They've specifically said they wouldn't tell people how much blood ... was found," he told Jesse Mulligan.
"If someone gets a negative test they may assume that there was no blood in ... their stool but that may not be the case."
Dr Cox said that under the Code of Rights, people should be given that information and more detail than just a pass or fail.
"The results that have been given thus far appear to have not met the legal requirements of the code of rights," he said. "In which case, people that have had tests done should have the results sent to them now - and that's thousands of people."
"The level of blood in the stool that would be reported as negative by the bowel screening programme in many other countries - Australia and Denmark, for example - they would be referred for a colonoscopy."
Dr Cox said the way tests were reported needed to be immediately overhauled so it was complying with the law.
However, the clinical director of the National Bowel Screening Susan Parry said the programme was in step with international guidelines.
"The Ministry is satisfied the National Bowel Screening Programme is operating consistently with HDC Code of Rights," she said in a statement.
She said patients could request their numeric results, but test results had to be reported in a way that was easily understood.
"It is quite clear in the information provided to participants in the National Bowel Screening Programme that the results of the screening test are reported as positive or negative, and they participate on that understanding.
"The Ministry of Health follows the advice of the manufacturer of the Faecal Immunochemical Test (FIT), and other countries that use the FIT in their national bowel screening programmes, to provide the result of the FIT as either positive or negative. The issue of the reporting of bowel screening results as positive or negative has been discussed and agreed by both the National Screening Advisory Committee and the Bowel Screening Advisory Group which comprise a range of experts across health and academia."
Dr Parry said there may be other medical reasons why there was blood in faeces, and patients were encouraged to go to their GP if they saw blood or if their bowel habits changed outside the two-year screening cycle.