How to... Request investigations

There are a number of factors to consider before ordering investigations, says Dr Louise Jourdier.

Ordering even a simple test requires careful consideration (Photograph: SPL)

How much thought do you put into the investigations that you order each day? When you write out a blood form, fill in an X-ray request or send your patient for an ECG, do you take the time to contemplate exactly what you will do with the results of each test requested?

Perhaps not always, and yet each investigation could be loaded with possible harm as well as benefit, and if nothing else, has cost implications.

Why test?
Investigations clearly form an important part of our armoury as GPs and there are many good reasons to organise tests. They can be integral in helping us to reach a diagnosis or to rule out worrying pathology, as well as playing an important part in screening and surveillance.

We often use tests to reassure and if done wisely, this can be entirely appropriate. However, there are many reasons for ordering tests, which may not be appropriate. It could be as a knee-jerk reaction to uncertainty, perhaps as a result of our own inexperience or our fear of litigation.

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Sometimes we may order tests just to show we are 'doing something' and I would be surprised if most of us could not be accused of using the promise of investigation as a way of wrapping up a difficult consultation from time to time.

We may also feel pressured into ordering tests by patients, their friends and family, or even by our medical colleagues. For example, an A&E doctor who advised the patient with back pain to see their GP for an MRI, or a GP colleague who promised to investigate if the patient's symptoms did not resolve; these scenarios can be particularly tricky because while it is important to practise medicine within the confines of what you believe to be right, undermining a colleague is also best avoided.

Investigation Costs
  • FBC £10.33
  • Basic biochemistry £15.49
  • Lipid screen £10.33
  • INR £9.29
  • MSU £9.41
  • Wound swab £10.84
  • X-ray (single view) £22.72
  • ECG plus report £25.82
  • DXA £78.49
  • 24-hour ECG plus report £98.11
  • Echocardiogram £166.27
  • Ultrasound scan (abdomen/pelvis) £82.62
  • CT with contrast £232.62

MRI with contrast (single area) £443.73

Source: Standard Investigations Pricing Index taken from National Institute for Health Research primary care costing template.

To test or not to test
What are the reasons not to investigate? This depends on circumstances, but a few things should run through your mind before you fill in the form.

First, could the test cause harm? For many radiological tests, the answer is 'yes', however small the radiation dose might be.

For other investigations, such as blood tests and cardiology investigations, the potential risks might be less obvious, but this does not mean there is no risk.

Take into account the discomfort or stress a test might cause the patient, the time the test will take and how difficult it will be for your patient to attend. Will they have to take time off work? Are they needle-phobic? Could the test increase rather than reduce their anxiety?

Second, consider the likelihood of picking up incidental findings, as well as the possibility of false positives and false negatives, which can cause unnecessary stress and lead to yet more investigations.

Third, think about how you will proceed having obtained the results. If nothing abnormal is found, will that be enough to reassure you and the patient? If abnormal, would the patient agree to the next stages, further investigation or treatment?

Sometimes we can find ourselves ordering tests for our own interest, without questioning whether the patient will benefit from the knowledge the test will bring. A classic example of this is to arrange an echocardiogram for an elderly patient with a murmur who then refuses any intervention.

Fourth, consider how you will manage patient expectations. If you request tests for patients every time, some will come to expect this and may not be satisfied in future until an investigation is performed. This can lead to an ever-increasing volume of unnecessary tests.

Finally, consider the cost of the test you are contemplating. There are financial implications to requesting any investigation and although none of us would want money to get in the way of good medicine, it is our duty to use our NHS budgets wisely.

A significant problem here is the lack of knowledge of specific costs. Did you know, for example, that a simple thyroid function test costs £28.92? Some of the most commonly requested investigations and their approximate costs are listed in the box above, which might just make you think twice next time you are about to fill in yet another request form.

Private healthcare
We should also mention investigations within the scope of private medicine. Although what makes good medical practice does not change for private patients, there are some additional factors to consider. Do patients who are paying for their treatment have a 'right' to demand investigations?

GPs can often feel as though they are under an obligation to refer a private patient for tests, even if we believe them to be unnecessary. There is also a growing number of private companies offering screening investigations as part of a general health check and patients may come to us for advice about whether these are required.

Private or NHS, ordering investigations for patients is something in which we could all invest a little more time and thought, to improve our clinical practice and to save money in times of financial difficulty.

So if nothing more, try to remember to ask yourselves these two simple questions before ordering even the most basic test:

1. What am I looking for?

2. Will I act if the test results are abnormal?

  • Dr Jourdier is a GP in London.

These further action points may allow you to earn more credits by increasing the time spent and the impact achieved.

  • Make a short presentation at your next practice meeting on the costs of common investigations and discuss with colleagues whether they are aware of these costs.
  • Audit the use of laboratory tests by your practice to work out how much the practice spends on testing.
  • Review your own behaviour in relation to ordering tests over the past week or two and assess whether there were any instances where the test was not absolutely necessary.

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