Overdiagnosis: How an overly thorough disease search harms
We often talk about cases where diagnosis takes a lot of time and requires changing several doctors. The opposite situation - that is, overdiagnosis - is no less problematic. Because of it, a person reveals a disease or condition that most likely will not manifest itself in the course of the patient's life, but knowledge of them will spoil this life anyway. This is not an "erroneous conclusion", because the diagnosis is established correctly - however, without setting it up in most cases nothing would have changed. At the same time, observation of the condition will take time for the patient and the medical staff, demand monetary costs and exert psychological pressure. That is why overdiagnosis is said in a negative way: it does more harm than good.
Text: Evdokia Tsvetkova, endocrinologist, author of Endonews telegram channel
Too many surveys
Overdiagnosis occurs primarily due to the fact that a person reveals variations in the structure of the body that will never cause harm, deviations from the (conditional) norm, which do not progress or progress too slowly, or anomalies that will disappear themselves. The reason is paradoxical - the higher the technical and laboratory capabilities, the more advanced methods we use, the greater the chance to find "something". In itself, this is good, because it helps to identify diseases in the early stages. But advanced technologies can be harmful if such surveys are conducted without evidence.
It is for this reason, and not because they are “sorry” that doctors do not send patients to research without a real reason. The task of the doctor is to decide whether a specific test is necessary in a particular situation. In order to level differences in education or personal opinion, these decisions must be made on the basis of research that has proven the feasibility of research in a particular situation. In order not to look for a doctor every time all the studies conducted on the topic, there are clinical recommendations - they are made up of expert groups who have already evaluated all the publications worthy of attention on this topic.
In Russia, the situation is not very good: for many specialties there are no uniform modern recommendations, and outdated standards have little in common with modern evidence-based medicine. In December 2018, the clinical guidelines law was finally approved. True, some associations, such as endocrinology, have been publishing such recommendations for years and years - and the problem of their simple non-compliance remains.
There are situations when the survey was conducted according to indications, but due to advanced methods, overdiagnosis occurred and a "surprise" was discovered that was not related to the reason for the test. For example, with CT scan of the chest or abdomen, you can accidentally detect a small benign adrenal tumor that doesn’t manifest itself - it is even called incidentloma.
Excessive autonomy
The more accessible and more diverse the diagnostic methods, the greater the chances of “finding something” - and the higher the temptation to use them. Commercial laboratories appeared, for which the referral of a doctor was not necessary — and, of course, minor deviations were found more often. Unfortunately, there are no statistics on this topic - it is not known how many people were in the wrong case who carried out this or that analysis and how many deviations from the norm were revealed. But if you at least once in your life donated blood in a paid laboratory and were worried about getting a blank with a highlighted red parameter that differed from the “normal range” by one, then you may also have been a victim of overdiagnosis.
To prevent this from happening, the feasibility of the analysis should be discussed with a competent specialist. You do not need to be tempted by PET-CT (positron emission tomography) of the whole body for a quarter of the price or the purchase of a glucometer "for self-control" if you do not have diabetes. Do not sign up for a paid ultrasound examination of the thyroid gland just because you felt a "lump in your throat." It is likely that it will be a manifestation of a completely different state (possibly emotional stress), but some nodal lesions may be found in the thyroid gland - and this is the case when early detection does not improve the results of treatment.
According to a study in South Korea, from 1999 to 2008, the incidence of thyroid cancer increased 6.4 times. But despite the more frequent detection, the mortality from thyroid cancer during this period has not changed significantly. At the same time, 95% of the neoplasms were small (less than 20 mm) and were detected by ultrasound screening. That is, the disease began to be detected more often at an earlier stage, and this had no effect on the prognosis: if it was later diagnosed and started to be treated, nothing would have changed.
Offset boundaries
The cause of overdiagnosis may be the displacement of the boundaries separating the "norm" and everything outside it. For example, sleep problems, sadness, or difficulty concentrating from time to time with most people. For some, these symptoms are intense and debilitating, but most often they are mild or fleeting. And if the former can benefit from diagnostics and treatment (for insomnia, depression, or attention deficit hyperactivity disorder), then for the latter there may be no benefit. The shift in the rate at which any bad mood or insomnia is presented as a disease, sometimes a strategy of marketing campaigns aimed at promoting a new drug or treatment method.
What it leads to and what to do
Overdiagnosis is a harmful and costly problem. Often, it leads to over-treatment without evidence, and its effects can be physical, psychological, social and financial. It's not just about money for paid tests. The time in the hospital and the work of the doctors are also expensive, and sometimes they are wasted - and they could be spent on a person in whose life the examination and treatment would really change something. As for the physical and psychological effects, they primarily concern patients. By themselves, tests and examinations are accompanied by certain risks, and if the disease is detected, the risk of anxiety and depression increases. To prevent overdiagnosis, the main thing a doctor can do is to follow the clinical guidelines and principles of evidence-based medicine.
In an ideal world, it would be enough to advise patients not to self-medicate and self-diagnose and follow the advice of doctors - however, it remains an open question that not all doctors are guided by clinical guidelines. Therefore, at least you should not be ashamed to ask questions about your health and about why this or that analysis is needed. If the information cannot be obtained from the doctor, you can use the Internet only by choosing the right sources. You can see for yourself the clinical guidelines (they are publicly available), read the media about evidence-based medicine (for example, “Just Ask” or “Actual Medicine”), ask a question on the forum or get a telemedicine consultation.
When need screening
For health care organizers, the question of overdiagnosis is different: what research should be used as a screening and how to conduct a prophylactic medical examination in order not to reveal too much? Complicated algorithms are used to plan the screening, and the selected tests must be sufficiently sensitive and specific. Sensitivity is the ability to give a positive result for all people who have a disease; specificity is, on the contrary, the ability of a test to show that all healthy ones are healthy.
In addition to these parameters, it is important to what extent the disease is common in the population, the same screening may not be recommended to everyone. There are special calculators that help calculate the value of the test as a screening. Taking into account all these data, recommendations are compiled - for example, in the USA they were put together in a convenient table with division by age.
According to the American guidelines, for all adults, doctors should measure blood pressure, ask a question about smoking, and have a blood test for HIV infection. It is also highly advisable to evaluate the use of alcohol, symptoms of depression and body weight. Hepatitis C virus testing is recommended for anyone born from 1945 to 1965 (and for people at high risk). From the age of 50 (or from 45 for African Americans), screening for colon cancer should be performed.
There are recommendations for screening separately for women: it is important that all women of reproductive age are recommended to be checked for violence from a partner. Cytological examination to exclude cervical cancer once every three years is shown to all women aged 21-65. Screening for breast cancer should be done every two years starting at age 50 (or more often in women at high risk). There are slightly different data, according to which women 45-54 years old are recommended annual screening, and from 55 years - every two years. Measurement of bone density (densitometry) to exclude osteoporosis, which women are more often exposed to, is always performed if a high risk was detected using the FRAX calculator, and from 55 years of age this test is desirable for all women.
Men are recommended to test for PSA (prostate-specific antigen) at the age of 40-69 years old at high risk of prostate cancer - but at the age of 70, this test is not advisable. Everyone, both children and adults, is recommended to check their visual acuity regularly (once every 1-4 years). For children and adolescents, too, there are similar tables. All other screening tests are carried out only in the presence of risk factors. And no matter how scary this or that disease may seem, you shouldn’t test it yourself. It is better to discuss with the doctor when it will be expedient to do (and whether it will be needed at all).
How are things in Russia
A good example of an important screening is screening newborns for congenital diseases. Their list in Russia since 2018 has expanded from five to eleven titles. Early detection of these diseases helps to avoid serious health problems and even death. With adults, things are much more complicated: in our health care system, there are no registers that, for example, will call you to the hospital for CT, to rule out lung cancer, knowing that you are 55 to 77 years old, your smoker index is at least 30 packs-years old and you continue to smoke (or quit no more than fifteen years ago). The system simply does not have such data. Therefore, it is necessary to communicate important information to the attending physician and remain within the limits of common sense: the fact that overdiagnosis exists does not mean that it is necessary to completely refuse from examinations.
Most likely, the future lies in electronic case histories, preventive questionnaires for risk factors and automation of these processes. Perhaps it will look like this: from a home computer you enter the personal account on the website of the unified health system and answer a number of questions. The database of clinical recommendations and approved screening programs are loaded into the system - and after filling in the questionnaire, the screen displays information on which studies need to be enrolled this year. If the situation is more complicated than usual, then you will be offered a remote consultation to clarify the data.
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