Screening programmes are an important public health tool. They can identify increased risk of disease among apparently healthy people, enabling them to access earlier, more effective treatment where appropriate.
Stakeholders often ask why, given its potential to save lives and improve health outcomes, more screening isn’t available to more people.
This article looks at how decisions on screening are made, the NHS screening programmes that are offered in Wales, and the risks/harms associated with screening. It aims to answer some of the most frequently asked questions about health screening.
Who decides whether to introduce a screening programme?
Approaches to screening in the UK are informed by the work of the UK National Screening Committee (UK NSC). UK NSC is an independent committee, accountable to the four UK chief medical officers.
UK NSC makes recommendations about the use of new and established screening programmes including:
- whether the benefits of a screening programme outweigh the harms;
- whether the overall benefits of a programme justify the costs;
- how a screening programme should be implemented; and
- what further evidence should be gathered.
You can find all UK NSC’s recommendations and supporting documents on the UK NSC website. Recommendations are reviewed regularly (usually every three years).
Each UK country sets its own screening policy, based on UK NSC’s advice. Wales has its own Screening Committee (as do Scotland and Northern Ireland), which considers the recommendations from UK NSC and provides advice to the Welsh Government and NHS Wales.
While the screening programmes offered are broadly similar across the UK, there can be some variation. For example, in all four UK countries, invitations to take part in bowel cancer screening end at 74 years of age. In England and Scotland, people aged 75 or over are able to request a screening test if they’d like one. This is not the case in Wales or Northern Ireland. (For more on this see our 2020 briefing for the Petitions Committee).
What conditions can I be screened for in Wales?
Public Health Wales currently offers the following national screening programmes across Wales, including three cancer screening programmes, and oversees the delivery of antenatal screening by local health boards.
This programme aims to reduce the number of ruptured abdominal aortic aneurysms (AAA) and deaths (an AAA is a swelling in the artery that carries blood from the heart to the abdomen). Men aged 65 who are registered as living in Wales will be invited for screening. This involves an ultrasound scan. Men over 65 who have not previously been screened can request a scan by contacting their local screening office.
This programme aims to find bowel cancer at an early stage. It involves a home test kit. People aged 51 to 74 who are registered with a doctor in Wales are offered bowel screening every two years.
This programme offers mammograms to women living in Wales aged 50 to 70 every three years. Women aged 70 and over will not be invited for screening, but can contact Breast Test Wales to request an appointment.
Women aged 25 to 64 are invited for cervical screening every 5 years. The cervical screening (smear) test looks for high-risk types of Human Papillomavirus (HPV) that can cause cell changes in the cervix.
Everyone aged 12 or over who is diagnosed with type 1 or type 2 diabetes and registered with a doctor in Wales will be invited for a diabetic eye screening test. The screening involves taking photos of the eyes to check for diabetic eye disease (diabetic retinopathy).
All babies born in Wales are eligible for newborn bloodspot screening (screening for rare but serious conditions). The sample for this test is usually taken five days after the baby is born.
All babies born in Wales are offered hearing screening during the first few weeks of their life.
All women who are pregnant are offered antenatal screening tests during their pregnancy.
NHS Wales has also published screening information and advice for people who are transgender or non-binary. An important point is that invitations for screening are based on how a person is registered with their GP and not the sex they were assigned at birth.
Will there be screening for lung cancer?
In 2022, UK NSC recommended targeted screening for lung cancer for people aged 55 to 74 identified as being at high risk of lung cancer. It said that the four UK nations should move towards implementation of targeted lung cancer screening with integrated smoking cessation service provision.
The Welsh Government accepted UKNSC’s recommendation in principle, and said it is working with Public Health Wales to explore how lung screening should be delivered in Wales. It said it is also working with the other UK countries to identify the optimal pathway.
Why is screening sometimes not recommended?
A key principle of population screening is that a screening programme should only be introduced if evidence shows the planned screening pathway, including further tests and treatment, will do more good than harm and at reasonable cost.
The tests used to screen large numbers of people tend to be simple rather than very accurate. They can identify whether there’s an increased risk of a disease/condition. Additional tests are usually needed to confirm its presence or absence.
No screening test is perfect. False negative or false positive results can mean people are either falsely reassured or unnecessarily worried. A false positive result may lead to someone having invasive or harmful tests or treatments which they don’t actually need. A false negative result may mean someone is not offered further diagnostic tests or treatment.
Some screening tests may also carry a small risk of physical harm, for example radiation exposure from a mammogram in breast screening.
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Example: prostate cancer Population screening for prostate cancer is currently not recommended in the UK. The most common way to screen for prostate cancer is to measure the levels of a protein called prostate-specific antigen (PSA) in the blood. UK NSC does not recommend screening for prostate cancer because:
Instead of a national screening programme, there is an ‘informed choice’ approach to PSA testing in the NHS. The prostate cancer risk management programme aims to provide clear, balanced information to men aged 50 and over (who don’t have symptoms of prostate disease) who proactively ask their GP about PSA testing. If a patient subsequently decides to have their PSA levels tested, the GP can arrange this. |
while screening can have huge benefits, it’s not always the answer to helping people with a particular health condition and resources might be better used elsewhere. For instance, it might be more effective for the government to invest in treatment services, or awareness campaigns so that people with symptoms visit their GP.
Article by Philippa Watkins, Senedd Research, Welsh Parliament
