Practice co-location with pathology centres has no effect on GP test ordering

Using data from the Bettering the Evaluation and Care of Health (BEACH) program, Prof David Studdert, from the School of Population Health at the University of Melbourne, and co-authors calculated test ordering rates of GPs in practices that were co-located with pathology collection centres (PCCs) operated by private companies, and compared them with test ordering rates of GPs working in practices located apart from these collection centres.

Prof Studdert said simple comparisons showed that GPs in co-located practices ordered more pathology tests than GPs in practices located apart from PCCs (40.3 tests compared with 37 tests per 100 GP-patient encounters). The GPs in co-located practices were also more likely to order one or more tests in any given consultation (16.8 per cent compared with 15.5 per cent).

But after controlling for other factors that influence test ordering, such as doctors’ age and practice size, the differences disappeared. GPs who practised side-by-side with PCCs had no higher rates of test ordering than other GPs.

“This answers an important health policy question,” Prof Studdert said.

“The Federal Government has been worried that the kinds of inappropriate influences and conflicts of interest we’ve seen infect doctors’ relationships with the pharmaceutical industry also exist in the pathology sector, and lead doctors to over-test patients.

“Our findings suggest that whatever happens in those relationships with pathology companies, it doesn’t seem to influence how many tests GPs order.

“To our knowledge, this is the first published study of whether doctors who have high levels of daily exposure to private pathology businesses are heavier users of the laboratory services of those businesses.

“The question has particular salience in the Australian health care system, where the pathology sector is much more heavily for-profit and more tightly integrated into primary care than in countries like the United Kingdom and Canada.”

Although the study findings should provide some comfort for regulators, Prof Studdert said they do not “close the book” on questions about over-testing. 

“There is still wide variation out there that cannot be explained. For instance, why are test ordering rates 10 per cent higher for GPs in Melbourne than GPs in Sydney?” he said.

“We need answers to these questions if we’re going to do better at controlling health care costs and improving the quality of care.”   

The Medical Journal of Australia is a publication of the Australian Medical Association.

The statements or opinions that are expressed in the MJA  reflect the views of the authors and do not represent the official policy of the AMA unless that is so stated.

CONTACT:     Prof David Studdert                              0407 083 444

                    Emma O’Neill                                      0432 758 734

                    (Media Officer, Uni Melb)