Reducing unnecessary test ordering can both improve care and improve environmental stewardship


The global movement ‘Choosing Wisely’ arose from conversations about appropriate clinician-led resource stewardship. Clinical resource stewardship encompasses multiple aspects including: financial, environmental/waste, time for patients, and clinicians’ cognitive load.


Healthcare is an expensive and carbon-intensive sector, generating 7% of the national carbon emissions in Australia. Although the carbon footprints of individual pathology tests are small, millions of tests are performed each year in Australia, and reducing unnecessary testing will be the most effective approach to reducing the carbon footprint of pathology.


Environmental sustainability can be summarised in a hierarchy of waste reduction – Avoid / Reduce / Reuse / Recycle. For pathology test ordering the opportunities for Reuse and Recycle are limited because of infection prevention. Reducing unnecessary test ordering can both improve care and improve environmental stewardship.


As many as half of all pathology tests may not be clinically indicated and some may even be harmful. They contribute significantly to the development of anaemia, which affects over 90% of ICU patients by day 3 of admission. Almost half of all critical care patients receive red blood cell transfusions during their stay, with up to one-third of all transfusions attributed to this so-called anaemia of chronic investigation.


Pathology tests are costly, amounting to 12% of the overall Medicare spending in Australia. Additionally, considerable time is spent performing, processing and interpreting tests.




To reduce unnecessary blood loss (harm), economic cost and environmental impact, we propose three steps for action:

1. Audit – Examine local test ordering practice and decision algorithms
2. Define – Develop clear guidelines for rational pathology test ordering
3. Educate – Design/implement an education intervention to support change where appropriate based on your audit


Step 1: Audit – Local practice and algorithms

1. Partner with your pathology service to access the data
2. Local practice should be examined to determine the number and type of tests ordered
3. Importantly, ask why are tests ordered?
4. Estimate the total financial cost of each category of test
5. Estimate the total environmental cost (CO2e) of each category of test (outlined in McAlister paper below)


Step 2: Define – Pathology test ordering & re-testing guidelines

1. Define what makes a test unnecessary. This requires delineating acceptable and unacceptable reasons for each test to assist in developing a guideline for your clinical setting.
2. Most reductions in unnecessary pathology test ordering (especially for inpatients) involve reducing repeat test ordering – so guidelines should specifically address when re-testing is indicated.


Step 3: Educate – Design an education intervention including:

1. Present the audit data to stakeholders
2. Facilitate stakeholder discussion regarding rationalisation of pathology test ordering
3. Assemble a multidisciplinary team of champions and educators
4. Propose an intervention
5. Implement a clinical guideline describing acceptable and unacceptable indications for tests
6. Utilise academic detailing to deliver the changes




This action guidance has been published in Australian Health Review. To read the full article, please click here




The Arterial blood gas (ABG) is the most commonly ordered pathology test in the ICU setting, often without a specific indication. Ordering patterns appear to be primarily driven by cultural factors such as testing a certain number of times per shift, at arbitrary time intervals, and before or after any changes in management. A 58-bed Level III ICU in Sydney performed 66,000 ABGs annually prior to an education intervention (which included the implementation of a clinical guideline) with more than half of these deemed inappropriate. The intervention resulted in a 31% bed-day adjusted decrease in ABGs (4.6 vs 3.1 per bed-day) without a demonstrable difference in patient outcomes. A repeat survey of reasons for testing showed that the proportion of inappropriate ABGs per bed-day decreased by over 70% (2.8 vs 0.8). This corresponds to annual savings of AUD $770,000, over 100 litres of blood, and one full-time equivalent staff member in labour costs. In addition, the reduction in carbon dioxide equivalent emissions of 49g per ABG resulted in a total reduction of 1038kg CO2e; the equivalent of driving 6,782km in a standard Australian car. The 58 ICU beds at this centre represent 2.4% of all ICU beds in Australia and New Zealand. Notwithstanding the variety in clinical practice and costs across the two countries, if a proportional 30% reduction in ABGs could be achieved across all sites this could result in annual savings of up to AUD $33 million, 4,400 litres of blood, 40 full-time equivalent staff (73 000 hours of labour) and over 43,000kg CO2e or the equivalent of driving 282,000km.




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