Dr Raghav Bhargava, Endocrinologist and Clinical Research Fellow, London, UK talks about health screening and its various aspects
It is the rampant practice of a range of preventative medical tests sometimes called a ‘health checkup’ for identifying health problems in apparently healthy people when it is not warranted. Private screening is not advocated as it is not clear if the benefit outweighs the harms of doing tests for diseases that are unlikely to be identified. This preventative screening is typically offered by private practitioners and laboratories with a menu like selection of ‘executive’ tests offering an assurance of preventing multiple diseases by getting a negative result. However, the most important part of any health checkup is to take a clear history of symptoms, which would not be present in an otherwise healthy person; an examination and only then if any, medical tests are offered. This decision is taken by a healthcare professional with the person seeking healthcare. From experience, increasingly health checkups start with a self-referred blood or imaging test, repeated many times prior to a second opinion. The main goal of such an approach then leads to correcting an anomaly on a report rather than explaining the harms and futility of unnecessary testing when there is no clinical correlation.
The reason why screening exists is to identify apparently healthy people who may have an increased risk of a particular disease. This decision is taken with long standing evidence and is part of national health guidance. It may detect a problem early, lead to more effective treatment, prevent complications, and lessen disease burden on our health infrastructure and society.
Currently, healthy screening exists for the following: cervical and breast screening in healthy women (using a smear test and mammogram), bowel cancer and abdominal aortic aneurysm screening in healthy older adults (using a home faecal test and ultrasound respectively)and diabetic eye screening in those with diabetes. There are also screening tests for healthy newborns including a hearing test and a blood spot test to look for rarer conditions, and scans and blood tests in normal pregnancy to spot genetic disorders, infectious diseases and to monitor the growth and development of the fetus. There are no routine blood tests included in any screening programme for healthy people.
It is also important to remember that these are screening tests in healthy people (typically quick and beneficial at a population level) and if return positive, then further diagnostic tests are required to confirm the presence of health conditions. Private screening can cause considerable anxiety to a person and false reassurance that they are healthy. The primary differences between screening and diagnostic tests are that the former is relatively cheap, to justify doing them in a large population and that they have a relatively higher sensitivity (less false negatives, i.e. less negative tests when disease actually present). While diagnostic tests are what health care professionals call the ‘gold standard’ test able to detect a disease in symptomatic people, have higher specificity (less false positives i.e. less positive tests when disease is actually not present) and typically more weight is given to accuracy and precision, rather than patient acceptability.
In India, where the health system is largely driven by private healthcare, payments driven either by out-of-pocket payment or private insurance a mechanism needs to exist to mitigate the harms of unnecessary health checkups in apparently healthy people. The demand for private screening has been born out a culture of ‘more is better’ and that a health care professional must prescribe tests or medication at each visit. It is also a result of managing the unrealistic expectations of people seeking validation to be labelled healthy. It is important for people to know what they are hoping to gain from a health checkup if they have no symptoms. It is also important to note whether private laboratories are accredited and routinely audited. Also, nearly every test is associated with unwanted harm. From pain at blood sampling sites or radiation with CT-scanning to complications with more invasive procedures. Private screening has increased by the disrupting access to routine health services caused by pandemic, teleconsultations that lack a physical examination by a health professional, ease of access to home testing and COVID which is still incompletely understood, and for which there is certainly no validated preventative screening test or health checkup. The limitations of applying screening tests to individuals are that they are not as accurate and precise as diagnostic tests so, a negative screening can still lead to the development of disease and if positive, can lead to difficult decisions of doing more invasive and risky tests. A negative screening test does not mean we should stop taking positive steps to stay as healthy we can though regular exercise, a balance diet, reduction in alcohol intake and stop smoking and tobacco intake.
The start of mitigating harms done by private screening can be by educational dialogues between healthy people and healthcare professionals such as the Choose Wisely campaign in North America. Education, that healthy people with no symptoms require screening only for the aforementioned conditions and if symptoms are present then to see a health care specialist rather than a private laboratory. It is equally important for the specialist to mention what tests are necessary, supported by evidence, not duplicative of other tests and the next steps to be taken if they are to be positive. Healthcare professionals, particularly dealing with second opinions in healthy people, need to reiterate that sometimes, no screening tests are required after a complete physical examination. This will not only reduce, the harms of unnecessary tests, the unease faced by people visiting health care settings and, prescriptions for medication that may be ineffective, expensive and harmful. The central health government should also facilitate evidence appraisals of screening tests nationwide and consensus should be taken by private laboratories that there should be no option of ‘self’ referral of tests and only to process the test if requested by a treating healthcare professional, who is directly caring for them.
Finally, it is important to note, that screening tests are developed to improve an entire country’s health. If one feels that they need a health checkup then it is best to speak to your healthcare provider and obtain reliable information.