Millions spent on unnecessary tests after normal colonoscopy
INAPPROPRIATE further investigation after normal colonoscopy could have cost as much as $25 million in the first few years of the National Bowel Cancer Screening Program (NBCSP), research suggests.
The results of a survey to be presented at Australian Gastroenterology Week (AGW 2012) in Adelaide this week show after a positive faecal occult blood test (FOBT) but negative colonoscopy, 65.6% of GPs, 19.5% of gastroenterologists and 14.2% of colorectal surgeons would refer for further investigation.
Gastroenterologist Professor Finlay Macrae, head of colorectal medicine at Royal Melbourne Hospital and study co-author, said following positive FOBT only a colonoscopy need be done to rule out polyps or cancer. Nothing further was required unless there was another clinical reason to investigate, such as indigestion or heartburn.
A total 298 GPs, gastroenterologists, surgeons and registrars were surveyed with 202 responses received. The questionnaire asked what the next step would be for a 55-year-old asymptomatic male with no family history of colorectal carcinoma, a positive FOBT and a normal colonoscopy.
Of 61 GP respondents 21.3% said they would do a repeat FOBT, while 41% and 3.3%, respectively, would recommend gastroscopy and capsule endoscopy.
Professor Macrae said the immunochemical FOBT used in the NBCSP was colon-specific and would not detect upper gastrointestinal bleeding.
“Blood coming from somewhere higher up, such as the stomach, is not detected because it is digested in the small bowel and by the time it gets to the colon it has lost the antigenicity that is the basis of the test,” he said.
Based on the survey results and the known costs of additional investigations, it was estimated that during the first 3.5 years of the NBCSP inappropriate investigations flowing from positive FOBT could have cost as much as $25 million.