Why Three Doctors' Heads Are Better Than One

New research shows that averaging doctors’ choices can improve treatment.

Posted Nov 25, 2020

Three Doctors’ Heads Are Better Than One
Source: austindistel/Unsplash

How many doctors does it take to change a light bulb?

Three. One to find a bulb specialist, one to find a bulb installation specialist, and one to bill it all to Medicare.

While popular jokes may question the competence of medical decision teams, new research suggests otherwise. A recent study found that groups of three or more doctors are usually better at making treatment choices than the average physician on their own.

The Wisdom of Crowds

It is a well-established fact that judgments of large groups are usually better than those of the individual people comprised within the groups. This phenomenon is called the “wisdom of the crowds” and has been evidenced across many different situations. A well-known example tells the story of a county fair guessing game, where visitors were asked to submit their best estimates for the weight of an ox. The closest guess was promised to be rewarded with a prize, yet the best estimate was that achieved by averaging the guess of every person who entered the competition. The group’s combined guess was only one pound off the ox’s actual weight!

The astonishing reliability of the wisdom of crowds is often attributed to the diversity in experience and knowledge across the members of a large group of people. With some people undershooting and some people overshooting, the most extreme guesses usually cancel each other out, and the group’s average ends up being surprisingly accurate. In fact, the value of a crowd depends on its size, independence of opinion, and diversity, which I discuss in this related article.

Collective Decision Making in Medicine

As outlined above, the benefits of group-based decision making are well-understood at a theoretical level. However, we are comparatively inexperienced in putting this theoretical knowledge to use in everyday decision making. How can the wisdom of crowds help us improve frequent, real-life choices?

An international team of psychologists and medical academics recently set out to provide new insights on this very question. The researchers investigated group-based decision making in healthcare and, more specifically, in the context of antibiotic prescribing.

Improving doctors’ and other prescribers’ decision making is critically important for increasing patient wellbeing and reducing mortality. Even though a formal medical education is required for prescribing drugs, no amount of education can rule out human error (for example, due to stress or fatigue). Indeed, in the context of antibiotic prescribing, an unusually high proportion of treatment choices seems to be inappropriate.

Even though international treatment guidelines recommend short courses of antibiotic treatment for certain types of bacterial infections, many doctors currently prescribe antibiotics for unnecessarily long durations. This can increase their patients’ risk of suffering from side effects. It may also promote antibiotic resistance, which is predicted to become a health threat greater than cancer over the next three decades.

To address the issue, researchers tested if and how the wisdom of crowds could improve decision making about the duration of antibiotic treatment. Based on survey data about antibiotic prescribing durations, the study in question used computer simulations for allocating individuals to prescriber groups of varying sizes. For these groups, individual treatment decisions were then combined and averaged. Finally, the group-based treatment choices were compared to those of individual doctors.

In line with the wisdom of crowds, the study results showed that groups made better treatment choices than individual doctors. The most successful technique for averaging the choices of a group’s individual members was to take the group’s median (i.e., to take the middle value of all treatment choices). The bigger the group, the higher were the number of prescribing decisions in line with guideline recommendations. However, even groups of only three doctors were found to outperform individual prescribers.

How to Improve Medical Treatment Choices

The study above extends previous research highlighting the importance of crowd wisdom in medical decision making. It suggests that forming groups of doctors and combining their treatment choices could lead to an overall improvement of healthcare, for example in the context of antibiotic prescribing.

Unfortunately, many publicly funded healthcare institutions suffer from a shortage of staff, meaning that most prescribers face challenging conditions such as time pressure and limited supervision by more senior colleagues. Relieving doctors of those pressures and enabling more opportunities for meetings and group-based patient consultations (such as hospital ward rounds with larger treatment teams) should therefore be a priority to improve medical decision making and ensure the highest standards of care.