Letter 5: HARM, BENEFIT, IMPROVEMENT, UTILITY, AND IMPACT
Harm, Improvement, and Benefit
Patients visit clinicians because they want to become better. What patients really want is treatment or some kind of solution to relieve their chief complaint or health problem.
Any treatment, whether drugs or a change in lifestyle, has three possible results: benefit, harm, or improvement.
Antibiotics reduce symptoms and mortality for those with pneumococcal pneumonia. However, antibiotics, like other medications, have "harm" or side effects – such as diarrhea, rashes, or, in rare occasions, anaphylactic reactions -- when they're given to a patient with bacterial infection and a patient who is actually healthy.
Each “sick-visit” between a patient and a clinician is a “diagnosis-treatment” encounter with two important considerations: how much harm the treatment will cause if the patient was not sick, and how much disease improvement the treatment will bring if the patient was really sick.
We would, therefore, define "harm" as: the adverse or negative outcome of treatment that would occur in a patient without disease (in other words, the side effects in healthy individuals).
"Improvement" is defined as how much better a patient with disease becomes as a result of the medication or treatment, compared with what her condition would be without the treatment, disregarding the side effects of the treatment.
"Benefit" is how much better a patient with disease becomes as a result of the treatment, compared with what her condition would be without the treatment, after taking into account the side effects of the treatment.
You might be wondering why a physician would give antibiotics to a person who is without disease. They wouldn't if they knew that the person does not have a disease. However, many patients with colds, fever, and cough are often diagnosed to have bacterial pneumonia, when in reality, what they have is a viral infection. Sometimes also, a chest X-ray shows “pneumonia” but the cause of the pneumonia is not bacterial but viral.
Here's an example illustrating harm, benefit, and improvement:
Bestbiotic (fictional drug) is given to patients with serious bone infection, and it reduces mortality from 50% to 20%. This means 30 fewer deaths from bone infection for every 100 patients treated. Unfortunately, Bestbiotic causes severe anemia resulting in death in 10% of the patients who take it, meaning it kills 10 patients for every 100 patients treated. In this example, the "improvement" is 30 fewer deaths, the "harm" is 10 Bestbiotic-related deaths, and the resulting "benefit" is 30 minus 10, or 20 fewer deaths.
Utility
Each individual has a different concept of harm and improvement. So, ideally, clinicians should ask the patient what they consider harm and benefit in any treatment they recommend. If the clinicians don’t ask, they will never know.
For example, a 25-year-old software programmer is about to lose her big toe from a proposed surgery. Although she does not like the idea of losing a part of her body, it would not greatly affect her income and job performance. The harm in this situation is not significant.
Another 25-year-old, a professional ballet dancer, is faced with a similar surgery -- the loss of her big toe. In this situation, the harm is great because of her occupation.
Clinicians can help their patients make judgments by giving them facts and an outcome study. However, the final decision on what to do should be left to the patient. There is really no pure “right” or “wrong” in many medical recommendations. In Decision Analysis terminology, the judgment of “goodness” and “badness” of medical outcomes is called “utility.” Perfect health is the best outcome; permanent physical disfiguration and death are the worst results.
One of the duties of clinicians is to help their patients make decisions that will lead to more positive outcomes as determined by their values. Clinicians can inject the concept of utility as a relative measure of “goodness” and “badness” of a disease or treatment outcome relative to other outcomes from alternative recommendations.
Clinicians can give patients a utility score of 0 to 1, from bad to good. The score system will have no units. It is a mental concept that is easier for both the patient and the clinician to arrive at a “better” and even faster judgment. As a rule, when our mind frame has numbers, “better” decision seems easier to make.
Another way of looking at utility is to consider it a subjective measurement of the likelihood of an outcome.
For example: Anaphylaxis from penicillin leading to death is a bad outcome. In terms of utility score, it is 0. However, the chance of it happening is low, about 1:200,000. Considering these two ideas together, most will take penicillin for appropriate indication because of the slim chance of anaphylaxis, and because of the better chance of benefit, which is shortening the length of infection and reducing the risk of rheumatic heart disease in patients with strep throat.
When clinicians discuss the risks and benefits of treatment with their patients, they consider both utility and likelihood when judging a particular outcome in the decision-making.
Impact
Unlike "utility," which is a subjective form of a bad-to-good measurement scale, "impact" simply reflects how much an outcome affects the patient compared to her not experiencing the outcome at all, regardless of the “badness” or “goodness” of the outcome.
Unlike utility, where lower is always worse and higher is always better, with "impact," the only consideration is how profoundly an outcome affects the patient. A happy event like a wedding, or an upsetting situation like a loved one being diagnosed with cancer, can result in a high level of “stress” despite the fact that one circumstance is pleasant and the other gloomy.
"Utility" refers to the subjective score from 0 to 1 of a given outcome or possible result of the treatment, while "impact" is the perception or feeling of living without the outcome compared with living with the outcome.
A severe adverse reaction from a medication can have a strong “impact” on the patient, as would an amazing cure from a serious disease. In both instances, an impact of 0.9 on a scale from 0 to 1 is possible. Think of an impact scale as an “importance score” for medical outcome.
At the end of the day, impact and utility give the same results in the final clinical decision.
In a nutshell, "harm" is the likelihood of the adverse or side effects multiplied by its "impact." "Improvement" is the likelihood of patient betterment multiplied by its "impact.”
End Letter 5 of 6
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