Misconceptions About Screening

There’s a huge amount of discussion about screening programmes from celebrities, campaigners and emotive media case studies. Unfortunately, a lot of this discussion is filled with misconceptions, misinformation and unrealistic expectations of what screening programmes are and what they can deliver. This has real lasting implications for patients and healthcare professionals. This needs to stop. Here’s some of the key parts of the screening conversation that you often don’t hear!

1. Screening cannot give you a ‘yes’ or a ‘no’ answer.

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Each person is slightly different, and this is the same with risk markers. To deal with this, some tests compare a person’s results to a range of ‘normal’ results, or a reference range. However, some healthy people’s results will fall outside this reference range (and vice versa). This may be because the test isn’t accurate enough or because of natural differences from one person to another.

2. Screening has costs.

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Despite celebrities and campaigners calling for more screening – for more people, more disease and for longer – screening is not without costs. These need to be weighed against the benefits for each screening programme.

3. Screening should not be for everyone.

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Costs of screening are often left out of the discussion. In every screening programme some people will get a positive result when they’re not at risk of developing the disease and some people who are at risk won’t be identified.

4. We should not screen for all diseases.

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Screening is only suitable for certain diseases. Before implementing a screening programme several factors need to be taken into account, including if an effective treatment is available for the disease being screened, if the screening test can accurately detect risk markers of the disease and if the screening test is safe.

5. We should only screen those most likely to benefit.

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Screening rarely benefits all sections of the population and should be for only those most likely to benefit. Increasing the number of people screened can end up causing more harm than good, so a number of factors including age, exposure and gender should be considered.

6. Screening tests are not diagnostic tests.

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Screening programmes aim to detect signs that a disease might develop in people who otherwise feel entirely well. Diagnostic tests are for people who have symptoms of a disease.

So next time you hear calls from celebrities and campaigners for more screening and discussions that only focus on its benefits, remember that:

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Screening should not be for everyone. It should not be for all diseases. It should not be about screening more people for longer. It should only be offered when there are more benefits than risks.

Read the new edition of Making Sense of Screening for more insights.