Blog: How True Information Becomes Misleading in Medicine
How True Information Becomes Misleading in Medicine
Teaches the Wrong Lesson
How diagnoses, statistics, and headlines become misleading without ever becoming false
Information becomes misleading not only when it is false, but also when a useful fragment is allowed to stand in for the whole.
I first read the story of Norman Cousins in college, and for decades I remembered it with remarkable confidence.
Cousins had terminal cancer. He left the hospital, rented comedy films, laughed constantly, and somehow laughed himself into remission.
It was a terrific story. Clean, hopeful, and easy to repeat. It may even have contributed to my decision to become a physician. It was also quite different from the story Cousins himself told.
He had suffered from a severe, disabling illness that physicians believed might be irreversible, but not terminal cancer. His account included medical care, large doses of vitamin C, changes in his surroundings, prolonged sleep, and comedy films that he believed gave him periods of meaningful pain relief. When he later wrote about the experience, Cousins acknowledged that one case carried little scientific weight. He had hesitated to tell it because he did not want to create false hope.
My memory had quietly rewritten it anyway.
Over time, the qualifications disappeared. So did the competing explanations. Laughter moved from one part of a complicated recovery to its apparent cause. What remained was the version most worth retelling: a dying man had laughed himself well.
The story had been compressed. Eventually, the compression became the story for me.
When the summary takes over
Human beings need summaries. Reality arrives with too much detail to reconsider from the beginning each time we make a decision.
A year of medical care becomes a paragraph in the chart. Thousands of observations become an average. A scientific paper becomes an abstract, then a headline, then something repeated in conversation. A person’s complicated experience becomes a diagnosis.
Usually, this helps. Trouble begins when we forget how much was removed. Apparently evolution forgot to weave in a system of footnoting for memories.
Philosophers describe one version of this mistake as a category error. The familiar examples are deliberately strange: What color is the number seven? How much does Tuesday weigh? After touring the classrooms, laboratories, library, and dormitories, where is the university?
The questions fail because they ask one kind of thing to provide another kind of answer.
The consequential versions are less obvious because they begin with useful information. A diagnosis describes part of a patient. A genetic variant may affect the probability of disease. A clinical trial tells us what happened among the people studied. A test score captures some aspect of performance.
None of these facts has to be wrong in order to become misleading. We only have to give one of them more authority than it can carry.
How True Information Becomes Misleading When Context Disappears
Medicine cannot function without categories. Diagnoses give clinicians a common language. They guide testing and treatment. For patients who have spent years without an explanation, a diagnosis can provide relief and direction.
Patients, however, do not arrive pre-categorized. They arrive with winding histories, conflicting responsibilities, complex relationships, financial constraints, prior treatment injuries, medication sensitivities, and bodies that rarely resemble the clean examples used for teaching. A diagnosis may organize part of that picture. With time, it may also begin to replace it.
I have watched this happen in ordinary clinical care. A label first explains a cluster of symptoms. Later, it is used to explain why the patient is upset, why treatment failed, why family members are frustrated, and what will probably happen next. Once the diagnosis seems to explain everything, fewer people keep looking.
The effect is especially visible with words such as “noncompliant,” “behavioral,” or “drug seeking.” Each label may refer to a legitimate concern. Once it enters the chart, though, it changes the posture of the next encounter. Cost, side effects, confusion, fear, transportation, prior trauma, and the practical burden of the treatment plan may receive less attention. A patient who arrived in 4K gets reduced to a lower-resolution version in the chart. The chart can be accurate and still narrow the field of view.
This is one reason experienced clinicians often return to the history even when the diagnosis appears settled. The question is not always whether the label is correct. Sometimes the better question is what the label has caused everyone to stop noticing.
What evidence can tell one person
A well-designed clinical trial may show that a treatment helped a proportion of patients under specified conditions. That information matters. Without population evidence, medicine drifts toward habit, anecdote, and personal confidence. The patient usually has a more personal question: Will it help me?
The study offers a starting point. It cannot contain the entire answer because the person in the room may differ from the study population in several important ways.
Clinical trials often exclude people with multiple illnesses, complicated medication regimens, unusual physiology, advanced age, pregnancy, impaired organ function, psychiatric instability, or previous treatment failures. In practice, a patient may have several of these features before the visit has properly begun.
Clinical judgment is the work of deciding how much those differences matter. It includes experience, but experience is hardly immune from error. Clinicians remember dramatic cases. We become attached to explanations that once worked. We may see patterns that are less stable than they appear.
Research protects us from some of those mistakes. Experience helps us notice where the research population and the actual patient begin to separate.
The same problem appears in genetics. Full siblings share, on average, about half of the genetic variation that differs among people. The words “on average” do considerable work. The statistic describes what is expected across many sibling pairs. It does not specify which variants two particular siblings inherited together or how those variants will interact with development, environment, behavior, illness, and chance.
One sibling develops a condition and another does not. One carries a recognized risk factor without developing the associated illness. Another becomes ill without the factor everyone had been watching. Nothing about this makes the statistic invalid. The statistic was never a complete biography of either sibling.
As scientific findings travel, that distinction often disappears. A variant associated with disease becomes “the gene for” the disease. A relative increase in risk begins to sound like a forecast. Biological influence is heard as fate.
How True Information Becomes Misleading in Medical Research
Scientific papers are generally narrower than the stories written about them. A responsible study defines the population, exposure, outcome, comparison group, follow-up period, and uncertainty. It also describes what the design could not establish. Those limits are easy to dismiss as academic caution, but they show the reader where the finding stops.
As the research moves outward, its boundaries tend to fall away. An association becomes a cause. It takes fewer words and sounds more decisive. A result in animals is promoted to a possible treatment for people. A group average becomes advice for everyone. An outcome measured over several months begins to sound permanent.
The headline may remain close enough to the paper to withstand a factual objection. The understanding it leaves behind can still exceed the research.
Cannabis medicine makes this problem unusually visible because the same substance appears inside several competing frames. To a regulator, cannabis is a controlled substance. In a study, it may be an exposure or an intervention. To a worried family, it may represent danger, hope, or desperation. To a patient with pain, insomnia, nausea, anxiety, or appetite loss, it may be one element in a much larger effort to function.
Each frame contributes something. The clinical question becomes distorted when one frame is allowed to settle the whole matter. A pharmacological discussion may also involve psychiatric history, family conflict, legal exposure, work demands, previous treatment failures, and the patient’s own interpretation of what changed. These details are not distractions from the science. They help determine how the science applies.
Individual complexity does not cancel population evidence. Patients can misread their experiences, and clinicians can overvalue unusual outcomes. An anecdote does not erase a probability. The point is simply that the probability and the person contain different kinds of information.
A better use of skepticism
Scientific uncertainty makes some people uneasy. If research cannot provide a guarantee, they begin to suspect that expertise has little to offer and that every explanation deserves equal consideration.
That is a comfortable form of skepticism because it releases the skeptic from having to distinguish stronger evidence from weaker evidence. A more serious approach asks what was measured, in whom, against what comparison, and over how much time. It asks who was excluded, which explanations remain possible, and whether a result about a group has been turned into a conclusion about one person.
Careful scientific language often sounds qualified because the qualifications carry meaning. “In this population,” “under these conditions,” and “during the study period” are not signs that researchers have nothing to say. They identify the borders of what can responsibly be said.
For years, I carried an appealing version of Norman Cousins’s recovery. It had a dying man, an unlikely intervention, and an ending that seemed to prove something reassuring about the mind’s influence over the body.
The account he published was less tidy. There was serious illness, medical care, several simultaneous interventions, pain relief, recovery, and genuine uncertainty about how those pieces fit together. That was not the version my college-aged mind retained.
I find that corrected version more useful now. It preserves the experience without asking it to become proof. It leaves the questions open without treating them as empty. Most of all, it reminds me that the easiest version to remember is often the one that discarded the most.
The next time a diagnosis, statistic, or headline seems to explain everything, what might come back into view if you asked what had been left out?
Reference
Cousins N. Anatomy of an illness, as perceived by the patient. N Engl J Med. 1976;295(26):1458-1463. doi:10.1056/NEJM197612232952605.
View the original articleKey points
- Accurate information can mislead when it is asked to explain too much.
- A diagnosis may guide care while narrowing what others notice.
- Population evidence cannot fully predict what will happen to one person.
- Good skepticism asks where a scientific claim stops.
Bring the whole clinical picture back into view
Dr. Benjamin Caplan and the CED Clinic team help patients interpret evidence within the realities of symptoms, treatment history, risk, and daily life.
