Sometimes 80 years old is not 80 years old
Why does something priced $19.99 seem less expensive than something priced $20? The phenomenon is called left-digit bias, and it affects health care decisions as it does purchasing choices. Left-digit bias is an example of a cognitive bias, which is a mental shortcut that leads to errors in decision making. Examples include confirmation bias (interpreting new information to confirm preconceived notions) and anchoring bias (overemphasizing early-acquired information). It turns out that doctors are susceptible to cognitive biases just like the rest of us.
A recent study published in the New England Journal of Medicine demonstrates that cardiologists are susceptible to left digit bias in treating older patients. The study reviewed patients who suffered heart attacks around the time of their 80th birthday. Physicians were more likely to perform a coronary bypass graft in patients in their late 70s, even those just about to turn 80, than those 80 and older. The age difference was often simply a matter of weeks, but nevertheless the distinction proved significant to physicians. And it was significant for patients too: patients who had the surgery were more likely to survive more than 30 days after the heart attack.
No two patients are the same
It is axiomatic that no two patients are the same. While the difference between 79 and 80 can be merely a couple of weeks or days, physicians are susceptible to contemplating irrelevant factors in diagnosing illness.
What does this mean for you and I? Identifying a cognitive bias is the first step to designing a system to overcome it. One example is that of medication dosage amounts: Physicians are commonly inclined to simply order the amount auto-populated by the health record. This has led to overprescribing medications – the subject of another blog post. By lowering these automatically input numbers, physicians are prescribing fewer opioids.
What efforts are developed to overcome left-digit bias are yet to be seen, but, again, identifying the problem is the first step to developing a solution.
Read the study here: Behavioral Heuristics in Coronary-Artery Bypass Graft Surgery
