Popularity vs Reputation: Content Matters for #CardioTwitter

Twitter is used by only a small number of interventional cardiologists, but it’s clear some accounts have many more followers than others: the question is, why? A look at the variables that affect popularity on the social media site suggests that it’s what cardiologists are doing with their time on the platform, not how many papers they’ve published or how influential others consider them to be as clinicians or academics, that determines how bright their Twitter star shines.

“We cannot assume that this translates automatically to other fields, but at least in our circle of interventional cardiology, the most popular accounts belong to people that actively produce content which is educational. They criticize trials or studies, they show cases and videos, they discuss techniques. This is the soul of good Twitter use in our field,” senior study author Davide Capodanno, MD, PhD (University of Catania, Italy), told TCTMD. “We have also to consider that this population is selected in a way because they were all faculty, so it doesn't apply to all interventional cardiology, of course, but it's a way to start.”

He added that he and his co-authors, led by Paolo D’Arrigo, MD (University of Catania), were surprised yet also pleased by the findings, which were based on monitoring Twitter activity over a 1-year period.

Published last week in JACC: Cardiovascular Interventions, the study of 1,423 faculty members of the TCT 2019 meeting found that only 26.8% had a Twitter account. The majority were male and had a United States affiliation.

D’Arrigo and colleagues hypothesized that three potential mechanisms might be responsible for boosting the number of followers for cardiologists: academic activity, energy spent on the platform, and individual charisma.

Academic activity was estimated using median values of the Hirsch index, a marker of academic proficiency that combines the numbers of published papers and related citations, as well as by gauging whether cardiologists belonged to large “cooperation networks,” which the authors defined as having a total of at least 150 co-authors over their academic career.

To look at energy spent on the platform, D’Arrigo and colleagues  examined the total number of tweets indexed by weeks on Twitter (activity index). Charisma was measured by the so-called Kardashian index (k-index). The latter, named after social-media sensation Kim Kardashian, is a real index that compares the number of followers a researcher has to the number of peer-reviewed citations they have amassed. A k-index greater than 5 signifies overblown scientific fame.

The primary endpoint was defined as “higher followers number,” meaning that a Twitter user was in the top quartile of followers, with 736 or more. To be considered “fast-growing,” a user had to gain 344 or more followers between baseline and 1 year.

Activity the Best Predictor of Followers 

Six factors were independently predictive of high followers number: top quartile for annual tweets (> 505 posts per year); k-index greater than 5; top quartile for followers (> 309); top quartile of activity index (2.6 tweets per week); large cooperation network; and US affiliation. Being in the top quartile of the Hirsch index, defined as 33 or more publications in peer-reviewed journals, was not an independent predictor.

Being in the top quartile of tweets was overwhelmingly the most predictive of cardiologists with fast-growing Twitter accounts (adjusted OR 12.66; 95% CI 5.13-31.24), followed by being in the top quartile of tweet activity (adjusted OR 7.10; 95% CI 3.35-15.07), and having a US affiliation (adjusted OR 3.48; 95% CI 1.75-6.93). The k-index lost predictive ability after adjustment (adjusted OR 1.63; 95% CI 0.63-to 4.21).

“The Kardashian index is a way to measure your role as an influencer, in a way,” Capodanno said. “We found it's something that looks important at the beginning, but then lost importance over time when we did 1-year follow-up.”

Capodanno said while the mathematical model doesn’t answer all the questions about why some people are more popular than others on social media, it shuts down the idea that meaningful dialogue about cardiology on Twitter is the sole domain of established academics.

“The message is really that what is important in gaining the followers is what you do on the platform; it’s not really about who you are,” he added.