Health Technology Assessment and Screening Programmes
The evidence basis for screening is whether early detection is beneficial, and if persons identified with early stage disease detected through screening have better health outcomes than those who come to clinical attention without screening.
It is not enough to know that a screening test actually identifies early diseases or conditions at a specific point of disease development. There must also be an effective intervention, which itself must be scientifically assessed.
The evidence to support or refute particular screening programmes is often limited. This may be because of the complexity of the screening issue, or the rarity of the conditions being screened for.
The best evidence for screening comes from randomised controlled trials.
UK National Screening Committee assess this evidence against the criteria for phasing the viability, effectiveness and appropriateness of a screening programme.
This committee reviews evidence of screening by regular review. This would include:
- A regular review when the current recommendations are not to offer population screening.
- A regular review when the current recommendation is to offer population screening.
- When new evidence is published or brings into question the current recommendation for screening.
- When a proposal is made to modify or make big changes to the current screening programme.
- When a proposal for a new topic which has not been previously reviewed by the UK National Screening Committee is submitted.
It must be remembered that the UK National Screening Committee’s remit was to evaluate screening in populations.
Here at The London General Practice, we are dealing with individuals and thus our recommendations, although different, must have clinical evidence behind them.
The guidance provided by this committee was updated on 20 May 2022. In particular, the screening committee’s remit was expanded in May so that it can now consider targeted and stratified screening in addition to its existing remit looking at screening offered to groups of people identified from the whole population.
Targeted screening can be used to select a high risk group using risk factors such as risk algorithms and this group would be one for whom screening would provide maximum benefits.
For the above average risk it can be helpful to increase individual risk or characterise an individual risk profile.
For apparently healthy asymptomatic or unaware patients then it would hopefully find the early stage of disease process.
Selected high screening should identify a selected high risk group, which will enable detection of a substantial proportion of cases.
Those with above average risk, the risk factor needs not to be causally related to disease.
In the apparently healthy, asymptomatic or unaware then it should help to find subclinical disease.
Here at The London General Practice, we consider that all patients should have targeted screening as defined by the UK National Screening Committee in its updated blog on 26 May 2022.
Stratified screening can also be used tailored to individual risk.
Both types of screening aim to detect a condition at a stage when treatment can be effective in order to intervene to alter its cause.
Screening for Conditions which the UK National Screening Committee Recommends
Abdominal Aortic Aneurysm
An aneurysm occurs when part of an artery swells, it is caused by a damaged blood vessel or a weakness in the blood vessel wall. The pressure of blood in the artery causes it to balloon out at the weak point.
An aneurysm can rupture if not treated or monitored. This can lead to internal bleeding and death.
The UK NSC recommended that abdominal aortic aneurysm screening could be offered to men aged 65 because:
- The ultrasound scan used to find aneurysm is very reliable and it is very rare for a man who has had a normal result to develop a large aneurysm.
- Once identified, AAAs can be monitored or treated, greatly reducing the chances of an aneurysm causing serious problems in the future.
The evidence showed that women should not be currently invited for screening as they are six times less likely than men to have an AAA and the risks of inviting them outweighed the benefits.
Bowel cancer is a general name given to cancer that begins in the large bowel. It can also be referred to as colon cancer and colorectal cancer.
Bowel cancer is one of the most common types of cancer diagnosed in the United Kingdom. Most people diagnosed with it are over the age of 60.
The UK NSC screening recommendation was based on the review of this condition that occurred in August 2018 and screening was recommended.
Here at The London General Practice we have adopted the American Cancer Society guidelines for screening rather than the UK National Screening Committee guidelines. This is because we are screening on individuals rather than populations.
Our screening involves offering CT colonoscopy to those patients aged 45 or over with a possible increased risk or those who elect to have it.
Find out more about Private Bowel Cancer Screening here.
In the UK, breast cancer is the most common type of cancer among women. It usually affects women over 50 years of age, having reached menopause.
It is possible for women of any age to be affected by breast cancer. In rare cases, the condition can also affect men.
Here at The London General Practice we follow the American Cancer Society guidelines for the screening of breast cancer and this is to offer a yearly mammogram to women aged 40 or over.
Find out more about Private Breast Cancer Screening here.
Cardiovascular Disease, High Cholesterol and Hypertension
The National Screening Committee did not recommend screening for high cholesterol but this was based on cost and ability for lipid clinics to cope with the workload.
Here at The London General Practice we offer this to all patients screened and then undertake the QRISK algorithm to evaluate the risk of coronary artery disease and whether further investigations should follow.
- Cervical cancer is extremely rare in women under 25, despite cervical abnormalities being quite common.
- The study found that for every 100,000 women invited for screening from the age of 20, the number of cervical cancers would not be reduced but an extra 8000 women would need further investigation and 3000 more would have unnecessary treatment.
- Frequent treatments for cervical abnormalities can increase the chance of premature births if a woman goes on to become pregnant.
Lung cancer is the second most common type of cancer in the UK and the most common cancer worldwide.
Around 38,000 people are diagnosed with lung cancer every year in the UK.
Smoking is the most common cause of lung cancer. Other causes include passive smoking and exposure to certain gases and chemicals.
The UK NSC screening committee did not recommend screening for this condition. However, here at The London General Practice we follow the American Cancer Society who recommend screening from the age of 50 for those who have smoked 20 or 30 pack years.
We also use the PLCO algorithm, which helps to stratify one’s risk for developing lung cancer based on smoking history and family history.
Find out more about Private Lung Cancer Screening here.
The prostate is a small gland found in men. It is located in the pelvis between the penis and the bladder. The main function of the prostate is to help in the production of semen.
Prostate cancer is the most common cancer in men and usually affects men over the age of 65.
The National Screening Committee does not currently recommend screening for this condition. However, once again, this is based on populations and not individuals.
The National Screening Committee felt that the PSA test was not accurate enough to detect prostate cancer that needs treatment. They also thought it can falsely find men who do not have prostate cancer. It can also miss cancers. They felt that many men might have to undergo unnecessary and often unpleasant tests and/or unnecessary treatment.
However, if interpreted correctly and if a sequential view of prostate PSA results are known then this can improve the diagnostic accuracy of the PSA test.
Here at The London General Practice we do offer PSA screening to men at high risk such as those with a family history or of black African origin. This can start from the age of 40.
Find out more about Private Prostate Cancer Screening here.
There is no reliable test for reviewing those at risk of stomach cancer but patients with any family history are offered H. Pylori testing and possible upper GI endoscopy.