It is time to expand our approach to assessing healthcare professional (HCP) affinity.

The Merriam-Webster dictionary notes affinity as both a noun and an adjective. As a noun, affinity means a relationship by marriage, a sympathy marked by a community of interest, a likeness based on relationship. This is the definition we generally associate with affinity. And this definition — one community, a one-way relationship, a singular likeness — can constrain our assessment approach.

As an adjective, affinity describes a type of chromatography — a chemistry technique for separating components of a mixture. Affinity chromatography is when a macromolecule is isolated and purified by passing it through a ligand for which the macromolecule has an “affinity” or linkage that causes it to be retained in that column.

Separation. Linkage. Retention. This chemistry-based definition can refine our approach to measuring HCP affinity.


HCP affinity is frequently assessed in aggregate at the channel level — what is an HCP’s affinity to email, SMS, social media, websites or face-to-face engagement? The gap here is that affinity will vary based on HCP place in the “customer journey” — awareness, acceptance, adoption — and the message communicated. Where and how I learn about challenges within a disease area may not be the same place or way I prefer to receive information on treatment choices. Message affinity itself will not be linked to channel affinity. Like the separation of substances, HCP channel affinity should be separately assessed by stage: awareness, acceptance or adoption — and also by message.


How can engagement be personalized if affinity assessment is not? Affinity is also often assessed at the “bucket” level: specialty, practice setting, region. Oncologists prefer in-person engagement. Institutional-based HCPs prefer online channels. HCPs on the West Coast prefer social media. But what do oncologists within integrated delivery networks in Arizona prefer? What is the linkage across buckets?

To be actionable, affinity assessment must link different criteria and expand to include what can be termed as “social determinants of healthcare professionals” — HCP age group, gender, ethnicity, etc. For example, 81qd HCP research found that the average age of physicians who followed other providers on social media was 35 years old with an even split of females and males, while the average age of physicians who did not follow other providers on social media was 53 years old, and 75% of these were male. Linkages must be assessed across different characteristics and criteria to understand what may drive a ligand or HCP’s “affinity.”


Affinity chromatography involves a binding reaction between two substances: A ligand is used to “capture” or “retain” a target molecule. To be effective, affinity data should go beyond capturing exposure to also include retention. What platforms and types of engagement support message retention? Content is retained by an HCP if it is specific and personalized for that HCP. Building specific and personalized experiences for HCPs will involve separation by customer journey and leveraging linkages across HCP characteristics. Who is delivering the message? HCP networks are a driver of message retention — messages delivered by connected HCPs have higher impact. What are the linkages that define whether the macromolecule, or message, will be retained?

Affinity chromatography has its limitations — it is labor intensive and requires customized materials. Similar challenges will be seen when applied to HCP affinity measurement. The approach outlined is data intensive and requires significant customization. But impact and value are clear. Affinity chromatography is known as “one of the most diverse and powerful chromatographic methods,” according to the book series Methods of Enzymology. Similarly, the opportunity to leverage a more diverse approach to affinity assessment will have a powerful impact on omnichannel engagement.

Successful affinity chromatography requires a deep knowledge and understanding of the nature of interactions between the target molecule and the ligand. In the HCP world, this means data mining and integration. HCP-level data mapping messages across customer journey, assessing networks, integrating HCP characteristics and “social determinants,” and linking to exposure, conversion and retention.

The time is now to expand these concepts from molecule to market.