A research team from Western Sydney University, Capital Markets CRC, University of Sydney and University of Adelaide did an analysis of publicly available, linked patient records within the electronic databases of the Medicare Benefit Schedule (MBS) and Pharmaceutical Benefit Scheme (PBS).
The results reveal:
49 per cent of patients on medications to lower their cholesterol did not have the recommended annual HDL-C test in a given year.
19 per cent of the same population received more HDL-C tests than were necessary.
the yearly expenditure associated with test overutilisation was approximately A$4.3 million, while the cost averted because of test underutilisation was approximately A$11.3 million per year.
Using the PBS data, the researchers collated the de-identified records of patients who received stable prescriptions of cholesterol lowering medications over a 7-year period from 2008 to 2014 - who could therefore be determined as being at high risk of developing heart disease.
As patient records are linked to the MBS, it was then possible to determine if these same patients received the recommended, annual High-Density Lipoprotein-Cholesterol (HDL-C) test from their GP.
Dr Evan Atlantis, from the School of Nursing and Midwifery at Western Sydney University, says the results suggest that one fifth of patients are receiving too many, unnecessary tests - while half are not having their blood cholesterol levels sufficiently monitored.
"Cholesterol tests are being administered in a haphazard manner - with some patients being tested too frequently and others not enough," says Dr Atlantis.
The BMJ Open paper explores several possible explanations for this finding. One points to a lack in continuity of care and to the fact that often people see multiple practitioners at once.
"If there is no designated 'medical home' for the patient, it is not clear who bears the responsibility for managing cardiovascular risk. In this scenario, it is not surprising that many individuals may miss their annual cholesterol tests," says Dr Atlantis.
"Another contributing factor may be the lack of continuity in medical records. It is entirely possible that practitioners are not aware that some of their patients are on cholesterol medications and therefore do not take the recommended action in ordering tests.
"Another possibility is that medical practitioners are making a clinical choice not to follow the current guidelines on blood cholesterol monitoring."
Dr Atlantis - together with co-researcher Dr Katy Bell from the University of Sydney - suggests that medical practitioners' widespread non-adherence may be evidence that the guidelines warrant review.
"If there is high level evidence that the recommended frequency of tests leads to improved health outcomes, then the potential underutilisation of these tests in Australia warrants further attention," says Dr Bell.
The study also identified the Federal Health Budget implications of the underutilisation of cholesterol tests.
During the study period, the yearly expenditure associated with test overutilisation was approximately A$4.3 million, while the cost averted because of test underutilisation was approximately A$11.3 million per year.
"While cost-saving, the long term health consequences of under-utilising HDL-C test are unknown and any increase in heart disease in Australia would result in a financial burden that cannot be ignored," says Dr Atlantis.
Farshid Hajati - who developed the methodology to conduct the study and analysed the data - pointed out that there is great potential for data of this type to benefit the public.
"The next step is to quantify the consequences of not receiving the recommended level of cholesterol testing, to strengthen the current recommendations on testing frequency."