GPs order diagnostic imaging tests such as X-rays and CT scans
at the rate of at least one test in every 13 consultations,
according to a report released today by the Australian Institute of
Health and Welfare.
Imaging Orders by General Practitioners in Australia
1999-00 suggests that if this rate is extrapolated to the
total number of GP-patient consultations in Australia, then
approximately 8 million diagnostic imaging tests were ordered by
GPs in 1999-00.
Plain X-rays were the most common type of imaging ordered
(63.7%), followed by ultrasound (25.7%), computerised tomography
(CT scans) (8.5%), magnetic resonance imaging (MRIs)(0.3%) and
nuclear medicine imaging (0.2%).
Director of the AIHW's General Practice and Statistics
Classification Unit at the University of Sydney, Professor Helena
Britt, says that GPs order about 60% of all imaging tests, with the
remainder being ordered by specialists.
'8 million tests is a lot of tests, of course, but from our
statistics, and reviews of the available guidelines, GP ordering
behaviour follows the guidelines in most areas.'
'That's not to say there isn't room for improvement. For
example, we think there is enough clinical evidence to suggest that
a reduction in ordering of spinal, ankle and knee X-rays may be
possible without affecting quality of care.
'We are also concerned about what we call "systemic blocks" on
GP ordering of MRIs and MRAs (multiple resonance angiograms).
Currently these tests are rebatable from Medicare only if ordered
by a specialist. These blocks sometimes lead the GP to order a less
suitable investigation.
'A more complex problem occurs with echocardiography-in summary,
our data and overseas research suggest that the quality of care
provided to general practice patients could be improved with
increased use of echocardiography.
'Our other major concern is the apparent relationship of large
practice size (11-15 GPs) with high rates of ordering, and overseas
evidence of high ordering rates when there is co-ownership of
imaging facilities and general practices. If corporatisation of
general practice leads to increases in both the number of large
practices and in co-ownership of imaging facilities and general
practices, it is possible that imaging order rates will rise.'
Other findings in Imaging Orders by General Practitioners in
Australia 1999-00 include:
- GPs in small rural areas are more likely to have high ordering
rates, possibly a result of rural GPs doing their own X-rays,
and/or conducting more detailed investigations before referral to a
specialist (access to specialists is comparatively poor in country
areas).
- The strongest independent predictor of high ordering rates is
the rate of consultations with new patients.
- High rates of management of musculo-skeletal, urinary and
female genital problems are also significant predictors of high
ordering rates.
24 August 2001
Further information: A/Professor Helena Britt,
Director, AIHW GP Statistics
and Classification Unit, tel. 02 9845 8151 (w), 0411 197 938
(mobile)
Media copies of the report: Publications Officer,
AIHW, tel. 02 6244 1032
Availability: Check the AIHW Publications
Catalogue for availability.