By Nellie Stidham
truth
\ ˈtrüth \
plural truths\ ˈtrüt͟hz , ˈtrüths \
Definition of truth
(Entry 1 of 2)
1a(1): the body of real things, events, and facts : ACTUALITY
(2): the state of being the case : FACT
(3)often capitalized : a transcendent fundamental or spiritual reality
b: a judgment, proposition, or idea that is true or accepted as true truths of thermodynamics
c: the body of true statements and propositions
(Merriam Webster)
It’s been widely found that the half-life of truth in the medical field, specifically surgery, is 45 years. What does this mean? It means that in 45 years, half of everything we believe is true today will turn out to be incorrect or obsolete. This seems like a scary notion when one thinks about all of the diagnoses being made in the world per day.
However, I encourage you to think of it from another perspective.
In 45 years, science will have advanced to figure out better therapies and more accurate ways of diagnosing illnesses, methods that we cannot fathom today. It should be reassuring that one study in 2002 found that “half of the nontrue conclusions in 2000 were obsolete rather than false” (Poynard, 2002). This means that a new test replaced an older therapy, or a new diagnostic tool was created that was more efficient. When this study distinguished between paper conclusions being found untrue or being found untrue/obsolete, the half-life differed. 45 years held for studies being proven untrue or found obsolete, however the half-life was 55 years if only counting studies being found false. This makes sense, as scientific information is always evolving, and it is easier to find a more accurate explanation than to outright prove something wrong.
For example, let's say a person turns orange. Paper A concludes that something in their diet caused them to turn orange. Paper B concludes that carrots were specifically the cause. 15 years later, paper C publishes that carotenemia causes people to turn orange, but can be due to excessive ingestion of carrots as well as certain green or yellow vegetables. So it turns out the person turned orange because of an excessive amount of carotene in their diet. Paper A is now obsolete, but not incorrect. Paper B is incorrect, because it wasn’t just carrots in the person’s diet that caused the orangeness but rather carotene, which can be found in a wider array of vegetables. For all we know, the person was eating too much kale.
The original paper that found the 45-year mark was published in 1997 by John C. Hall and Cameron Platell. They decided to find the half-life of truth in surgery based on the “hypothetico-deductive model of Karl Popper,” which states that “an assertion is true if it corresponds to, or agrees with, the facts” (Hall & Platell, 1997). Direct your attention to the claim that “the truth” is based on “fact.” Isn’t what is considered “fact” relative to the time period? After all, it used to a “fact” that the earth was the center of the universe. It is often emphasized in science classes that there is no way to prove a hypothesis correct; one can only prove a null hypothesis incorrect. If one wanders down this rabbit hole of thought, how can we ever accept what is true if eventually what we know as true will be obsolete?
An article by Poynard et al. hypothesized that papers exemplifying “evidence-based medicine” would have a longer half-life than those not. The paper classified “evidence-based medicine” as meta-analysis and randomized trials, and found that they did not have a significant advantage over non-randomized studies. It is interesting to consider this finding, as non-randomized studies are typically thought to be less valid than their randomized counterparts. What might have happened is that only the most valid non-randomized studies were selected by the two scientific journals studied. The journals selected, Lancet and Gastroenterology, are highly regarded in their field and therefore this finding may not hold true when a larger sample is considered.
So how should we regard the finding that articles based on evidence-based medicine performed just as well as those not? While this outlook can seem pessimistic on the surface, it signals that reliable peer-reviewed journals are good at weeding the bad science out. Overall, the conclusion that should be drawn is that time betters science, and that highly-regarded peer-reviewed journals exemplify the best science of the time.
Just think: the earth was once believed to be the center of the universe. What “facts” of our time could be completely wrong?
References:
Hall, J. C., & Platell, C. (1997). Half-life of truth in surgical literature. Lancet, 350(9093), 1752. https://doi.org/10.1016/S0140-6736(05)63577-5
Lascari, A. D. (1981). Carotenemia: A Review. Clinical Pediatrics, 20(1), 25–29. https://doi.org/10.1177/000992288102000103
Merriam Webster. (n.d.). Truth. Retrieved March 26, 2019, from https://www.merriam-webster.com/dictionary/truth
Poynard T, Munteanu M, Ratziu V, Benhamou Y, Martino VD, Taieb J, et al. Truth Survival in Clinical Research: An Evidence-Based Requiem?. Ann Intern Med. ;136:888–895. doi: 10.7326/0003-4819-136-12-200206180-00010