Vol. 9 Lessons from a 100-Year-Old Heavy Smoker

"I have a 90-year-old heavy smoker in my neighborhood. So, cigarettes have nothing to do with it."

I sometimes hear this kind of talk from patients. And unfortunately, I have actually seen medical professionals who use similar logic when speaking to patients.

This is a cognitive bias known as "survivorship bias." People who smoke and live long lives are visible. However, those who died in their 60s or 70s because of smoking are no longer there. If you base your conclusions only on what you can see, you will end up with a conclusion that is the exact opposite of reality.

Alternatively, it can be said that people unconsciously collect events that reinforce their logic so that they can believe in "what they want to believe." Especially in the recent era of social media, AI is designed to automatically display only videos and posts that you are interested in or that align with your own ideology.

The relationship between smoking and lung cancer, heart disease, and COPD (chronic obstructive pulmonary disease) is one of the most solid pieces of evidence in modern medicine, repeatedly demonstrated by epidemiological studies on the scale of hundreds of thousands of people (Doll & Hill, 1950). The single case of "someone who lived a long life despite smoking" does not overturn this evidence.

This pattern of thinking, where one "speaks for the whole based on a single case," is widely seen, not just with smoking. "I know someone who felt worse after taking blood pressure medication. It seems it's better to have somewhat high blood pressure." "An acquaintance of mine felt unwell after getting vaccinated." These are all cognitive distortions that replace probability and risk with personal anecdotes.

People with a strong tendency toward this distortion are more likely to believe anecdotes over evidence and are easily drawn into scientifically unfounded information or conspiracy theories. Being in the field of preventive medicine, I feel this keenly. I know, unfortunately, that there are doctors who fall into this way of thinking. There are not a few, even among doctors with status and reputations.

This is actually related to a fundamental problem in the current medical world: that such "basic scientific literacy" is not necessarily required as an essential skill to become a doctor, a specialist, a department head, or a professor.

The latest treatments and testing methods can appear attractive.
However, surprisingly, "boring" behaviors that have been used since long ago—quitting smoking, abstaining from alcohol, and exercising—are often the methods with the highest preventive effect.

Reference:
Doll R & Hill AB. "Smoking and carcinoma of the lung; preliminary report." Br Med J. 1950;2(4682):739-748. PMID: 14772469.

*The content of this note article is the author's personal view. It has no relation to the views of the medical institution to which the author belongs. I have paid close attention to the accuracy of the content, but I would appreciate it if you could point out any inappropriate content if it should exist.

#BasicsOfPreventiveMedicine #LifestyleHabits #RiskPerception #ScientificThinking #SurvivorshipBias