Do I Really Need That Test? Understanding Medical Overdiagnosis
There is a broadly held assumption in medicine — shared by patients and, to a significant degree, by physicians — that more information is always better. If a test exists, and a test might find something, then ordering the test is the cautious and responsible choice. The alternative, not ordering it, feels like a risk.
This assumption is understandable. It is also, in a meaningful number of clinical situations, wrong.
The problem of medical overdiagnosis — finding and treating conditions, or pursuing findings, that would never have caused harm if left undetected — is one of the most significant and least discussed challenges in modern healthcare. It is not a fringe concern raised by skeptics of medicine. It is a mainstream topic within medicine itself, the subject of major research programs, a high-profile campaign by leading physician organizations, and a growing body of evidence that has changed clinical guidelines for several common screenings and tests.
The Choosing Wisely initiative, launched in 2012 by the American Board of Internal Medicine Foundation, has identified more than 600 tests, procedures, and treatments that evidence suggests are commonly performed but may offer little benefit — and sometimes cause real harm — in certain patient populations. The initiative involves more than 80 medical specialty societies, each of which has contributed lists of practices in their specialty that are worth questioning. It represents a professional consensus, built from within medicine, that the reflex toward more testing needs to be examined rather than indulged.
Understanding where that reflex leads — and how to evaluate whether a recommended test is appropriate for your specific situation — is one of the most practically useful things a patient can learn.
How Overdiagnosis Happens
Overdiagnosis is not the same as misdiagnosis. A misdiagnosis means the wrong condition was identified. Overdiagnosis means a real finding was identified — but one that would never have caused harm during the patient's lifetime, and that once identified, sets off a chain of clinical responses that produce harm of their own.
The clearest examples come from cancer screening. When prostate cancer screening with PSA became widely adopted, it identified many prostate cancers that would never have caused symptoms or shortened the patient's life — slow-growing, indolent tumors in older men who were statistically more likely to die of something else. But identified as cancer, those tumors were treated — with surgery, radiation, and their associated risks of incontinence and erectile dysfunction — producing harm in patients who would have been better served by watchful waiting or no intervention at all. The same dynamic has been documented with certain breast cancers found through mammography, with thyroid cancers identified incidentally, and with certain lung nodules detected on CT screening.
The problem isn't the tests themselves — some screening saves lives. The problem is the application of those tests to populations for whom the balance of benefit and harm is unfavorable, and the clinical reflex to treat everything that is found rather than to carefully evaluate whether treatment is warranted.
The incidentaloma cascade, discussed elsewhere, is the downstream expression of this problem: an unexpected finding on imaging leads to follow-up imaging, which leads to a specialist consultation, which leads to a biopsy, which leads to a procedure — each step individually defensible, the cumulative result potentially more harmful than the finding that started it.
The Choosing Wisely Initiative and What It Tells Us
The Choosing Wisely recommendations are organized by specialty and are specific enough to be practically useful. A few illustrative examples across specialties convey the scope of what the initiative has identified.
In cardiology, routine annual electrocardiograms for patients without symptoms or known cardiac disease have been identified as offering little benefit to low-risk patients while potentially leading to false positive results, further testing, and unnecessary anxiety. The test is appropriate when there is a clinical reason to order it — it is not appropriate as a routine screening tool for everyone.
In radiology and emergency medicine, CT scans for minor head injuries in adults without specific risk factors have been identified as commonly performed but rarely revealing meaningful findings in low-risk patients — while exposing patients to radiation and sometimes identifying incidental findings that initiate unnecessary further workup.
In oncology, routine imaging surveillance for certain cancers in remission has been questioned in situations where the evidence for benefit from surveillance imaging is not strong and where the findings that surveillance produces often don't change outcomes.
In primary care, routine annual complete blood counts and chemistry panels for healthy adults without symptoms or known conditions have been identified as producing more false positive results — and the anxiety and follow-up testing those generate — than meaningful clinical findings.
The thread running through all of these is the same: a test that is valuable in the right clinical context becomes problematic when applied reflexively to patients for whom the clinical context doesn't support it.
When One Test Leads to Many: The Cascade in Practice
The incidentaloma cascade is worth examining specifically, because it is one of the clearest mechanisms through which overdiagnosis produces real patient harm.
The cases that came to Pilot Rock Medical Navigators illustrate this concretely. In one, a routine chest X-ray revealed what appeared to be rib fractures. Without the clinical context — the patient's history, the age of the findings, the absence of any current clinical concern — that finding would have initiated a workup for pathological causes of fractures: cancer, osteoporosis, metabolic bone disease. Each of those hypotheses would have generated its own tests. The cascade would have been set in motion.
A thorough review identified that the fractures were old, well-healed, and clinically irrelevant. The cascade never started.
In another case, an incidentally discovered nodule in a sensitive anatomical location — found in the course of imaging done for an unrelated reason — had prompted a recommendation for biopsy under general anesthesia. The biopsy would have involved real risk: anesthesia complications, procedural complications, recovery. A careful expert review of the imaging characteristics, in the context of the patient's clinical picture, determined that the biopsy was not warranted. The patient was spared a procedure that carried meaningful risk for a finding that didn't require it.
In both cases, what prevented the cascade was the same thing: someone who looked carefully at the full picture, evaluated the finding in context, and asked whether the next step was genuinely warranted rather than simply following the path the finding had suggested.
Why Physicians Order Tests That May Not Be Necessary
Understanding why unnecessary testing happens — given that the evidence against it is available and the professional organizations have been explicit — helps patients engage with the question of whether a recommended test is appropriate without assuming that an unnecessary recommendation reflects incompetence or bad faith.
Defensive medicine is one of the most significant drivers. Physicians who practice in a medical-legal environment where undertreating is a source of liability have a structural incentive to order tests — because ordering tests demonstrates that they were thorough, and because missing something that a test might have found creates legal exposure. A physician who orders every plausible test and a finding is missed has a different legal position than one who used clinical judgment to not order a test and missed something. This asymmetry in liability shapes clinical decision-making in ways that aren't always in the patient's best interest.
Time pressure makes clinical judgment harder to apply. A physician who has 15 minutes with a patient and finds a borderline result or an ambiguous symptom has two choices: apply careful clinical reasoning to decide whether the finding warrants follow-up, which takes time, or order a test to resolve the uncertainty, which takes less time in the appointment but may create more downstream complexity. The 15-minute appointment structure creates pressure toward the second option.
Patient expectations contribute to the dynamic as well. Many patients expect that a thorough appointment involves ordering tests, and physicians who don't order tests can face the implicit or explicit message that they haven't done enough. The cultural equation of more testing with better care is reinforced by both sides of the clinical relationship.
Revenue incentives in fee-for-service medicine mean that ordering tests generates revenue — for the ordering physician, for the institution, for the laboratory or imaging center. These incentives don't make physicians dishonest, but they create an environment in which the default toward ordering is financially reinforced.
A Framework for Evaluating Whether a Test Is Appropriate
Patients who want to think carefully about whether a recommended test is appropriate for their situation can apply a set of questions that help evaluate the recommendation rather than accepting or rejecting it reflexively.
What specific question will this test answer? A test that is ordered to investigate a specific clinical hypothesis — to confirm or rule out a specific diagnosis, to evaluate a specific symptom — is more likely to be appropriate than one ordered as a general screening measure or to "check everything." Asking what specific information the test will provide helps evaluate whether that information is genuinely needed.
How will the result change what happens next? This is perhaps the most useful question in evaluating any medical test. If the result is normal, what happens? If the result is abnormal, what happens? A test whose result — in either direction — won't change the clinical management is a test whose value is limited. A test that, if abnormal, will initiate a specific and appropriate clinical response is a test with clear value.
What are the risks of this test? Not all tests are equal in their risk profiles. A blood draw carries minimal risk. A CT scan involves radiation exposure. A biopsy carries procedural risks including bleeding, infection, and in some locations, nerve damage or other complications. Understanding the risks of the test itself — not just the risks of what it might find — is part of the complete picture.
What are the chances this test will find something meaningful versus something incidental? For imaging studies in particular, the likelihood of finding an incidental finding — something unrelated to the clinical question being asked — varies by the type of imaging and the area of the body being imaged. A patient who understands that a CT scan of the chest has a meaningful probability of finding a pulmonary nodule that will require follow-up is better positioned to decide whether the scan is worth ordering than one who doesn't know this.
Is this test recommended by major clinical guidelines for a patient with my characteristics? Clinical guidelines from major professional organizations represent the synthesis of evidence about which tests are appropriate for which patients. A test that is recommended by guidelines for patients with specific risk factors, symptoms, or age ranges is on different footing than one that is being ordered outside those parameters. Asking whether the test falls within guideline recommendations for a patient with your specific profile is a reasonable and answerable question.
What happens if I wait? For tests that are being ordered to evaluate symptoms or findings that may resolve on their own, waiting a defined period before testing is sometimes the evidence-based approach. Understanding whether watchful waiting is appropriate — and what specifically would change the recommendation — provides a middle path between testing immediately and not testing at all.
The Patient's Role in This Conversation
Asking whether a recommended test is necessary is not an act of obstruction. It is an act of informed engagement with a medical recommendation — the same kind of engagement that any physician would apply to their own care.
Physicians who are asking the same questions themselves — who are practicing in a way that is consistent with the Choosing Wisely principles and the evidence on overdiagnosis — will welcome these questions. A physician who is confident that a test is appropriate can explain specifically why: what clinical question it will answer, how the result will affect management, and why the expected benefit outweighs the risk of the test and the potential cascade it might initiate.
For patients who have been told a test or procedure is necessary and aren't sure whether to proceed, an independent review of the clinical reasoning — by a physician who has the time to look at the full picture and evaluate whether the recommendation is supported by the evidence — can provide the clarity that a brief appointment often doesn't.
The goal is not fewer tests. It is appropriate tests — ones that are ordered because the clinical situation genuinely warrants them, that are likely to produce information that will change what happens next, and whose expected benefit outweighs their risk and the downstream consequences they might initiate. That standard, applied thoughtfully, is what distinguishes good medicine from more medicine.
————————
If you or a loved one has been told a test or procedure is necessary and wants an independent assessment of whether it's appropriate, Pilot Rock Medical Navigators can help. Book a free 15-minute introductory call to discuss your situation. Learn how Pilot Rock can help →