Quaternary prevention: protecting the patient from excess

A 52-year-old woman returns to the unit with the result of an imaging test ordered by another service, to investigate back pain that has already passed. The report describes a small nodule in an organ nobody was looking at. She is frightened, wants to know whether she needs more tests and asks whether it is cancer. The doctor knows that findings of this kind are usually harmless, but also knows that each new test can bring another finding, another wait and another worry.

Situations like this are part of the routine of primary care. Medicine offers more and more tests, more screening and more labels, and almost all of them seem reasonable when seen in isolation. The problem appears in the sum. Quaternary prevention is the name given to the task of protecting the person from interventions that tend to do more harm than good. This text presents the origin of the concept, the two definitions in use, cascades of care, the pressures that push the doctor toward excess and what to do in the consultation.

Key points

• Quaternary prevention is the action of protecting people from medical interventions that tend to cause more harm than benefit.
• The concept was born in family medicine, from the difference between the disease the doctor looks for and the illness the person feels.
• The original definition looked at those who feel ill without having a disease; the more recent definition applies to anyone, sick or healthy.
• Cascades of tests after incidental findings are common and bring psychological, physical and financial harm.
• Excess is pushed by fear of litigation, discomfort with uncertainty, pressure from colleagues and perceived patient demand.
• The trusting relationship, waiting with method and shared decision-making are the main tools of protection.

Summary

• What quaternary prevention is
• Where excess comes from
• Cascades of care
• Why the doctor investigates beyond what is necessary
• The relationship as a tool of protection
• Waiting with method
• What to do in the consultation
• Limits and misunderstandings
• Frequently asked questions
• Final checklist

What quaternary prevention is

The idea was proposed in 1986 by a family doctor and entered the dictionary of the World Organization of Family Doctors (Wonca) in 1999 (Martins, 2018). The original definition describes the action of identifying the patient at risk of overmedicalization, protecting them from further medical invasion and suggesting ethically acceptable interventions (Martins, 2018).

The starting point is a simple distinction. There is disease, which is the theoretical construct the doctor works with, and there is illness, which is the person's subjective experience (Martins, 2018). The clinical encounter can be described in four fields: the doctor looks for disease and the person may or may not feel ill (Jamoulle, 2015). When the two axes cross, four situations arise. The person may be well and without disease, the ground of primary prevention. They may be well and have a still silent disease, the ground of secondary prevention. They may be ill and have a disease, the ground of treatment and tertiary prevention. And they may feel ill without the doctor finding a disease, the quadrant originally reserved for quaternary prevention.

The typical example of that last quadrant is symptoms without medical explanation. Faced with them, the recommendation is that the doctor avoid invasive tests with potential for harm (Martins, 2018). The person truly suffers, but the endless search for a disease that does not appear can add risks without adding relief.

The author of the concept himself sums up the idea as a version of the old principle of first do no harm, and recalls that this attitude runs through all of the doctor's activity, not just one kind of consultation (Jamoulle, 2015). The concept was adopted by family doctors on several continents (Jamoulle, 2015).

Over time, it became clear that the four-quadrant model had a limit. People in the other three quadrants are also at risk of excess (Martins, 2018). A healthy person may be screened without need, someone with a silent disease may be treated beyond what would bring them benefit, and a chronically ill patient may accumulate procedures of little value.

That is why a new definition was proposed: quaternary prevention is the action taken to protect people from medical interventions that tend to cause more harm than benefit (Martins, 2018). In the graphic representation, it no longer occupies a corner and moves to the center of the axes, applying to everyone (Martins, 2018).

Another reading, published by primary care authors, reaches a similar conclusion. They describe quaternary prevention as an arrow that crosses the other three forms of prevention (Norman and Tesser, 2019). They recall that, at first, the focus was the so-called worried well and people with symptoms without medical explanation (Norman and Tesser, 2019). And they propose two scenarios of demedicalization: one for people without symptoms, in the field of primary and secondary prevention, and another for people who feel ill or have a disease (Norman and Tesser, 2019).

This same reading sums up the task in three points: recognize the risk of excess medicalization, protect the person and offer ethically acceptable alternatives (Norman and Tesser, 2019). The third point is what keeps quaternary prevention from becoming simple refusal. Protecting is not abandoning.

Protection, in this sense, is active: it requires explaining, proposing and following up.

Where the excess comes from

Part of the excess is born of good intentions. Preventive medicine, the habit of treating risk as if it were disease and commercial interests create pre-diseases, lower the cut-off points and shift attention from the sick to the healthy, from the older to the younger and from the poorest to the richest (Tesser, 2017). When the threshold of a diagnosis falls, people who were well start to be treated as patients (Martins, 2018).

General checkups are another example. A review cited in the discussion of the concept shows that they reduce neither disease nor mortality, but they increase the number of new diagnoses (Martins, 2018). Possible harms include false positives, incidental findings, overdiagnosis and cascades of new tests (Martins, 2018). Overdiagnosis, here, is the diagnosis of a condition that would remain indolent for the rest of life (Norman and Tesser, 2019).

There is also a shared error of perception. Both patients and doctors tend to overestimate the benefits of interventions and underestimate their harms (Martins, 2018). When both sides of the table err in the same direction, the scale tips toward doing more.

Screenings illustrate the problem well. They are aimed at people who feel healthy and can bring overtreatment through overdiagnosis, false positives and anxiety (Bae and Jamoulle, 2016). The same authors argue that screening should be adjusted to each person and recall that stopping a screening can also be an important decision (Bae and Jamoulle, 2016). The text about the three drivers of overdiagnosis details how screening, threshold and incidental finding combine.

Cascades of care

A cascade of care begins when a test shows something unexpected and that finding leads to new tests, consultations and procedures. A national survey with 376 internists showed that almost all of them had already experienced cascades after incidental findings, including cascades that led to no result relevant to the patient (Ganguli, 2019).

The reported harms were of several kinds. About seven in ten doctors had seen patients suffer psychological harm, about one in six had seen physical harm and more than half had seen financial harm (Ganguli, 2019). The doctors themselves also suffered: about seven in ten reported loss of time, about half reported frustration and some reported anxiety (Ganguli, 2019).

One fact stands out. When recalling the most recent cascade, about a third of the physicians acknowledged that the test that started it might not have been appropriate (Ganguli, 2019). In other words, part of the cascades could have been avoided at the first decision, before any finding. As solutions, about six in ten physicians suggested guidelines, and many mentioned decision support tools (Ganguli, 2019).

In practice, the cascade usually follows a recognizable script:

• a test is ordered without a clear clinical question;
• the result shows a finding unrelated to the complaint;
• the finding causes anxiety in the patient and discomfort in the physician;
• a new test is ordered to clarify, and sometimes brings another finding;
• each step adds waiting, cost and some procedure risk;
• in the end, it is often concluded that there was nothing that needed treatment.

That is why the best defense against the cascade comes before it. The question about what to do with the result and the estimate of the probability before the test help avoid the first step.

Why physicians investigate beyond what is necessary

A second survey with the same internists used simulated cases to understand the reasons for cascades. More than half said they would follow a specialist's recommendation even when it contradicted the guideline, and about six in ten said they would investigate more when there was no evidence to guide the decision (Ganguli, 2020). Among the associated factors were fear of litigation, discomfort with uncertainty and the perception that the patient wanted more tests (Ganguli, 2020).

A qualitative study with 13 family physicians described excess as the sum of unnecessary investigations and treatments with no benefit or with potential for harm (Alber, 2017). The participants identified direct and indirect causes and recalled that the family physician is at the starting point of the diagnostic process (Alber, 2017). Whoever opens the door to investigation also has the chance not to open it.

In interviews with 12 specialists on the topic, pressure from colleagues appeared among the barriers (Otte and Llargués Pou, 2024). One of them summed up the idea by saying that, if the physician does not order tests regularly, they may be seen as negligent (Otte and Llargués Pou, 2024). The study listed six barriers: pressure from colleagues, awareness and screening campaigns, cognitive biases, cultural factors, the complexity of the topic itself and industry influence (Otte and Llargués Pou, 2024).

Focus groups with 38 family physicians described pressure coming from all sides (Cordey, 2024). The authors called this everyday practice of ordering a little more to protect oneself ordinary defensive medicine, and spoke of a shared vulnerability between physician and patient (Cordey, 2024). Diagnostic uncertainty comes in here as a driver: the less the physician tolerates not knowing, the more they tend to order.

Pressure from the patient is not always what it seems. A review on medically unexplained symptoms shows that the physician's feeling of being pressured is often imprecise and that, frequently, it is the physician who suggests the intervention (Olde Hartman, 2013).

The relationship as a protective tool

Almost all the sources arrive at the same place: the relationship between physician and patient is the main instrument of quaternary prevention. Among the four factors identified by the specialists interviewed, the relationship comes first, alongside training, the design of the health system and influencers (Otte and Llargués Pou, 2024). The family physicians in the qualitative study cited the trusting relationship among the strategies against excess (Alber, 2017).

The reason is practical. Saying that a test is not necessary only works when the person trusts the one saying it. When physician and patient disagree about a screening, the relationship suffers, and the proposed way out is to keep trust and share the decision (Bae and Jamoulle, 2016). A relationship built over time allows the physician to propose waiting without seeming dismissive.

Listening also protects. In consultations for symptoms without a medical explanation, psychosocial clues appear in almost every encounter (Olde Hartman, 2013). The same review points out that medical training is still very much focused on disease (Olde Hartman, 2013). Recognizing these clues, as discussed in the text about empathy in the consultation, often addresses the real concern better than a new test.

Shared decision-making completes the picture. Explaining likely benefits and harms, admitting uncertainty and agreeing on the next step makes refusing a test a choice made together.

Waiting with method

One of the most cited strategies is well-founded waiting (Alber, 2017). It is not inaction. It is an active decision to observe, with criteria for acting if the picture changes.

A commentary on the concept recalls that not doing is not as easy as accepting to do (Widmer, 2015). The same author insists that quaternary prevention does not give up on caring and requires time and skills (Widmer, 2015). Faced with a still undifferentiated complaint, the doctor has a duty to respond, and that response is not necessarily a test (Widmer, 2015).

For waiting to be safe, it needs a few elements:

• a main hypothesis explained to the person in plain language;
• clear alarm signs that justify coming back before the agreed date;
• a set return date, not left open;
• a record in the chart of what was agreed;
• the willingness to change the plan if new information appears.

Planned reassessment is what separates watchful waiting from abandonment. Time, in this sense, works as a diagnostic test with no adverse effects, as long as someone is watching.

The primary care reading cited above adds that, in prevention, the principle of not causing harm should prevail, and that quaternary prevention calls for restraint, caution and a less automatic application of protocols (Norman and Tesser, 2019). It is not about ignoring guidelines, but about applying them to the person in front of the doctor.

Situation	Risk of excess	Protective alternative
Symptom without a medical explanation after adequate assessment	Repeated and invasive tests without a new question	Explain, welcome, agree on alarm signs and follow-up
Low-risk incidental finding	Cascade of tests and consultations	Discuss the likely meaning and decide together whether investigation is worthwhile
Screening without a clear indication for age or risk	False positive, overdiagnosis and anxiety	Screening adjusted to the person, including the decision to stop
Lowered diagnostic threshold	Healthy person labeled as sick	Explain what the label actually changes in prognosis
Referral to another service that goes against the guideline	Test with no likely benefit	Talk with the colleague and the patient before proceeding

What to do in the consultation

The family doctors interviewed in one of the studies made practical proposals. They include improving communication, using evidence-based medicine, relying on clinical skills, experience and intuition, and investing in training and in social movements against excess (Cordey, 2024). The experts heard in another study cited four enablers: evidence-based medicine, personal experience with a questioning attitude, public campaigns on the topic and experience in low-resource settings (Otte and Llargués Pou, 2024).

That last point yields a curious observation. When a resource, such as blood collection tubes, became scarce, it started being used more judiciously (Otte and Llargués Pou, 2024). Scarcity forced the question that abundance allows skipping.

In the consultation, a few questions help apply quaternary prevention. What is the clinical question this test answers? What will I do if the result comes back abnormal, and what will I do if it comes back normal? Does the person understand the likely benefits and harms? Is there a less invasive alternative, including waiting? Who will follow up the result and what comes next? These questions echo those in the text about low-value tests and practices.

Protection also applies to what is already underway. Reviewing old treatments, reassessing screenings that have lost their meaning and removing labels that do not change the person's life are forms of quaternary prevention. The text about how harm reaches the patient shows that excess rarely comes from a single decision.

Teamwork helps. Nurses, pharmacists and other professionals can notice the buildup of interventions before the doctor does, as the text on interprofessional clinical reasoning discusses.

Limits and misunderstandings

Quaternary prevention can be misinterpreted. The comment already cited warns of the risk that it is confused with denying care (Widmer, 2015). Protecting against excess does not authorize omission. A person with signs of serious illness needs investigation, and quaternary prevention does not change that.

The concept is also not opposed to prevention. The arrow that crosses the other forms of prevention serves to calibrate them, not to eliminate them (Norman and Tesser, 2019). Vaccines, well-indicated screenings and effective treatments remain part of care.

Another limit is that the boundaries between disease and illness are blurred (Bae and Jamoulle, 2016). It is not always easy to know whether a complaint is a symptom without explanation or the beginning of a disease that has not yet shown itself. That is why waiting needs criteria and a return visit, and why the text on what overdiagnosis is not recalls that diagnostic error by omission also exists.

Finally, the evidence on the topic comes largely from qualitative studies, surveys and reflection texts. They describe the problem and the perceptions of professionals well, but there is still little direct measurement of how much quaternary prevention reduces harm. The studies with doctors and specialists themselves were done with small groups and in specific contexts (Alber, 2017; Otte and Llargués Pou, 2024).

Frequently asked questions

Is quaternary prevention the same as not ordering tests?

No. It is protecting the person from interventions that tend to cause more harm than benefit (Martins, 2018). Tests with a clear clinical question and a probable benefit remain indicated.

Does the concept apply only to symptoms without explanation?

It started that way, but the most recent definition applies to anyone, ill or healthy (Martins, 2018). Screenings, treatments and diagnoses can also be excessive.

What is a cascade of care?

It is the sequence of tests, consultations and procedures that follows an unexpected finding. In a survey with doctors, almost all had already experienced cascades with no relevant result for the patient (Ganguli, 2019).

What if the patient insists on the test?

It is worth checking whether the pressure is real, because the doctor's perception is often imprecise (Olde Hartman, 2013). Understanding the concern behind the request and deciding together usually works better than giving in or refusing without a conversation.

Is waiting not risky?

Safe waiting has an explained hypothesis, alarm signs, a return date and a record. Well-founded waiting appears among the strategies cited by family doctors against excess (Alber, 2017).

How to deal with the fear of a lawsuit?

Fear of a lawsuit is among the factors associated with cascades (Ganguli, 2020). Recording the reasoning, the conversation with the patient and the follow-up plan protects more than a test without indication.

Final checklist

• Before ordering a test, define the clinical question and what you will do with each possible result.
• Explain probable benefits and harms, including false positive and incidental finding.
• When faced with a low-risk incidental finding, discuss its meaning before investigating further.
• Adjust screenings to the person and consider when to stop.
• When you choose to wait, agree on alarm signs and a return date, and record the plan.
• Periodically review treatments, labels and screenings that no longer make sense.

References

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