The Science Behind Opinion Leadership

Many articles and blogs are written about how to select the perfect opinion leaders for your product, stage of development and disease as well as how to engage and deploy them for maximum impact. While these are interesting and important topics, we want to take it one step further and understand how the science and psychology behind how opinion leadership works. You can find our previous blogs on the topic by clicking these links - When should you start opinion leader engagement?, 7 tips for building and maintaining successful relationships with opinion leaders, and 5 Reasons for Working with Rising Stars and Young HCPs.

In the life sciences it is rare that you come across a paper from the 1990s - let alone the 1950s – that still informs developments today to a degree that you want and need to read it. This topic took us down that path and all the way back to a publication about imitation written by Gabriel Tarde in 1903 – The Laws of Imitation (which we, admittedly, only skimmed in the English translation rather than read in the original French).

The Diffusion of Innovations

Fast forward about 60 years to the work of Everett Rogers, a professor of Communication and Journalism. In his seminal 1962 book “Diffusion of Innovations” he developed a framework for assigning people to different categories depending on how readily they adopt new technologies and innovations. The five categories, still used today, are:

  • Innovators, the 2.5% of the population who adopt a new technology or product the minute it becomes available or ideally even before. Innovators are fascinated by technology and have a high tolerance for uncertainty and failure.
  • Early Adopters, 13.5% of the population also adopt very early but unlike the innovators they are attracted to the potential benefits of the innovation rather than driven by the desire to get their hands on the coolest new technology. Early adopters rely on their intuition and vision when deciding whether to adopt, rather than references.
  • Early Majority roughly one third of people, open to new technology but are pragmatic and want to see references and proof that the innovation works before they jump on the bandwagon. Late majority, also about one third of the population, adopts an innovation when it is proven to the point that is has become the standard, and finally
  • Laggards, the remaining 16% who’s attitude towards adoption of innovations can be described as “I’ll adopt when hell freezes over”. Some more recent publications have started calling this group “traditionalists” rather than using the more offensive sounding term “laggards”.

These categories were later adopted by Geoffrey Moore’s in his classic book “Crossing the Chasm” that focuses on the challenge of attracting early majority customers after successfully convincing innovators and early adopters.

Diffusion in the Pharmaceutical Industry

Most of this research on diffusion of innovations is general in nature or focuses on the adoption of consumer or high-tech products.

The first publication of note specifically exploring the diffusion of a drug goes back to the mid-1950 when Coleman, Katz and Menzel, sponsored by Pfizer, undertook a study “The Diffusion of an Innovation Among Physicians” on the adoption of tetracycline by physicians. The results showed that ads in medical journals, detailing by sales representatives, and education of physicians through peer reviewed journal articles created awareness but were insufficient to persuade the average physician to adopt the new antibiotic. The study found that targeted peer-to-peer communications played an important role in convincing physicians to give tetracycline a try.

Since then curiously few studies on the topic have been published.

Do Opinion Leaders Speed Up Adoption?

The idea that a small number of influential individuals, or opinion leaders, can exert strong influence on individuals in decision making scenarios goes back to the 1940 and 1950 when Lazarsfeld, Katz et al 1 developed their two-step-flow model of communication. This model postulated that influence flows from the media through influencers to their followers in a two-step process, rather than directly from the media to the general public. At the time the two-step model was considered a new paradigm, which, by the 1970s, had itself turned into the accepted paradigm or the “guiding theme for diffusion and marketing research.” - (Burr, 1999). Leveraging key influential individuals among the customers to disseminate information and foster adoption of new products – from consumer products to new drugs or medical devices – is the logical consequence of that paradigm shift.

One of the experiments that highlights the value of opinion leaders was undertaken by Valente and Davis in 1999 2.

They generated hypothetical networks and studied adoption of innovations in these networks depending on whether these 10 first adaptors were opinion leaders, randomly chosen people “randoms”, or rather people at the periphery of the network, so-called “marginals”. What they found was, that picking 10 opinion leaders resulted in fairly rapid and complete uptake of the innovation, while adoption driven by “randoms” – and even more so by “marginals” - was slower and never achieved 100% during the time of the experiments. A figure (figure 2) from the original paper illustrates this by showing the adoption curves.

Figure 2: Diffusion Network Simulation with different Initial Adopters from Accelerating the Diffusion of Innovations Using Opinion Leaders by Thomas W. Valente and Rebecca L. Davis.

The explanation for this dynamic is that opinion leaders – established and well-connected individuals - are not necessarily early adopters of a new product or technology. Early adopters tend to be people who bridge several networks and are often found at the at the periphery of those networks.

For an innovation to be adopted widely it has to slowly percolate through the network from early adopter to network member after network member until it reaches an opinion leader. Once an opinion leader adopts and promotes that innovation, adoption by the other network members is swift.

This dynamic explains the initial lag time seen in experiments using “randoms” or “marginals” as starting point and provides a rational for how taking the innovation directly to opinion leaders shortens that lag time, creates critical mass more quickly and leads to rapid adoption of the innovation by the members of the network.

Opinion Leader vs Early Adopter

The model above explains why diffusion of an innovation is accelerated once opinion leaders adopt and endorse an innovation and provides the rationale for the pharmaceutical industry to engage KOLs. It also emphasizes the importance of selecting those individuals who have the most influence within the network and are therefore best positioned to drive adoption with minimal lag times.

It also leaves us with a conundrum: as mentioned above, opinion leaders are generally not early adopters. Opinion leaders are central network members that serve to reduce risk and uncertainty for others and provide the references that early majority members need before they embrace a new product. As such, opinion leaders cannot afford to be too far ahead of the pack.

However, early adopters are critical for quick diffusion. The ideal scenario, therefore, is to find an early adopter who also is an opinion leader, or convince an opinion leader to adopt early, which – going back to the tetracycline study – might be feasible by fostering meaningful peer-to-peer communication between a healthcare provider and medical affairs, especially field medical staff.

An interesting question we couldn’t find an answer to, despite our deep dive into papers authored by sociologists and communication experts, is whether – in the age of consolidating physician practices - engaging opinion leaders who have an early adopter among their colleagues would accelerate the rate of adoption by opinion leaders. Subjected to the influence of their innovation-embracing colleagues, the more pragmatic opinion leaders might just jump on board more quickly.

Working with young, rising star opinion leaders who are at the forefront of their disciplines, might also be a way of getting the best of both worlds and ensure faster adoption.

Summing It All Up

Surprisingly little research has been published about diffusion of innovation and the role of opinion leadership specifically in the pharmaceutical industry and as it pertains to the adoption of new drugs and medical devices by physicians. However, research spanning more than a century supports the notion that opinion leaders can drive diffusion and adoption of innovations and therefore effectively engaging them can be critical in driving the adoption of new drugs or medical devices.

“Physician prescription behavior is significantly influenced by the behavior of research-active specialists, or “opinion leaders,” in the physician’s reference group.” - Sage Journals


  1. Katz, Elihu and Paul Felix Lazarsfeld (1955), Personal Influence; the Part Played by People in the Flow of Mass Communications, Glencoe, IL: Free Press. [return]
  2. Valente T, Davis R. Accelerating the Diffusion of Innovations Using Opinion Leaders, Annals, AAPSS, 566 (1999) [return]