Over-testing

First Do No Harm: a guide to choosing wisely in general practice

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Last revised: 01 Nov 2022

Over-testing occurs when:

the result of the test would not alter how you manage the patient or their symptoms, or change their health outcomes
there are more potential harms than benefits from taking the test
the tests have poor measurement properties, and/or are done more frequently than necessary.¹

What causes over-testing?

Defensive medicine, which can occur if the clinician has concerns about medico-legal liability. These concerns might stem from delayed diagnosis, or difficulty dealing with uncertainty. ²
Some complementary and alternative (CAM) practitioners may advise patients that they can avoid paying for specific tests if they ask a GP to request them through Medicare.²
Poor-quality information sources, resulting from patients researching their symptoms and presenting at the clinic with a proposed course of action.³ Medical literature and internet sources often contain exhaustive lists of tests associated with conditions, but many of these recommended tests do not improve clinical management or patient safety.
Financial incentives for testing companies operating under a fee-for-service model.
Lack of information continuity. The patient may not tell their regular GP about tests they have already had through another GP or a private pathology lab that does not require a GP consult.

Harms from over-testing

Physical harms from over-testing: Testing can be painful and anxiety provoking and may expose the patient to radiation.²
Overdiagnosis: More testing can lead to an increased likelihood of making a ‘diagnosis’. Tests are increasingly sensitive and therefore may pick up an ‘incidentaloma’, which could lead to treatment that is unnecessary, expensive, and potentially dangerous.
False-positive and false-negative tests: Some tests can give false-positive results, which leads to unnecessary further testing or treatments, or false-negative results, which provides inappropriate reassurance that can delay correct diagnosis and appropriate treatments.
Non-medical harms:
- Patient’s financial costs. These could include out-of-pocket payment for procedures, as well as time off work for tests, treatments and recovery, and loadings and exclusions that insurance companies might apply as a result of particular test results.²
- Harms to the health system: Creating delays, and wasting the health system’s finite resources (eg money, equipment, peripherals and people) that could be used for patients who need those tests
- Environmental harms. Over-testing can create unnecessary waste from products used in the testing process, such as syringes.

How to help prevent over-testing

Consider if the test results will change your management of your patient: If the results will not change how your patient is managed, then do not order the test.⁴
Ask your patient if they have undertaken any tests for the same issue, and if so, when: The lack of information continuity from other providers can lead to over-testing. GPs also have an important role in educating patients around the cost to the health system of 'double testing' or unnecessary testing.
Undertake shared decision making with your patient: Communicate your thoughts to your patient clearly and thoroughly. Invite them to be an active partner in the management of their health and encourage them to ask questions.⁴
- Use evidence-based, accessible information appropriate to the patient’s health literacy so they understand the risks and benefits of the test or treatment they are asking about and can make informed decisions.³
- Provide information about appropriate diagnostic testing, such as RACGP’s Appropriate diagnostic testing that has more information on this topic.
- Use precise language when talking about screening and diagnosis (for example, use the term ‘raised blood pressure’ instead of ‘hypertension’).³
- Depending on the test or screening, talk to your patient about:
  - the uncertainties in medicine and the advantages of not rushing to a diagnosis.³
  - the high sensitivity of modern screening tests.³ Some screening tests can detect an ‘abnormality’ that many people have but which is not the cause of their symptoms and cause them harm. But this can result in an unnecessary ‘diagnosis’, along with associated unnecessary harms, and may also stop you and your patient from focusing on the cause of the symptoms.

Watchful waiting. This can often be safely implemented by monitoring the patient’s condition, but not providing treatment immediately.⁵ To implement properly:
- advise your patient of symptoms that they should look out for, especially red flags⁶
- depending on the condition, ask your patient to return at an agreed time for a review, or sooner if symptoms appear, get worse, or change
- reassure your patient that they can take some time to think about the information they’ve received, and come back if they have any questions.
Check your practice if you are unsure about ordering investigations:⁴ This could include:
- Reading relevant clinical guidelines (you can view All guidelines by topic on the RACGP website)
- Seeking assistance from a supervisor or peer.
- Analysing your test ordering, by answering the following questions:⁷