Leveraging Peer-to-Peer Networks in Pharmaceutical Marketing - Innovation and Marketing in the Pharmaceutical Industry - page 464

same medical group. The differences in peer influences could be among the strength
of influences or types of drugs.

15.5.3 Influence of Product/Patient/Physician/Payor

Characteristics

A major area for research is the effect of patient and product characteristics, and the
features of the health care system on peer influence and contagion. This would extend
the more general literature on characteristics of products or innovations that influence
collective adoption or diffusion. The existing studies do not take into account the patient
profile, the patient insurance status, the physician insurance acceptance status, and many
other factors which may be important in the formation of the physician network. The
physician referral network may be different based on the patient insurance status. There
may be differential effects in how contagion works for different drugs, perhaps depend-
ing upon the therapeutic category, chronic vs. one-time use drugs, critical vs. healthy
patients, high vs. low uncertainty in therapy, and so on. These findings may also apply
to the adoption of medical devices, surgical procedures, guideline adherence, and
generic adoption, which may be of interest not just to pharmaceutical firms but also to
hospitals, health systems, insurers, and the government. There may be differences based
on stage in the product life cycle of the drug. For example, Iyengar et al. find contagion
in introduction of a new drug, while Nair et al. ( 2010 ) find that opinion leaders are influ-
ential only in the times following an uncertainty.

15.5.4 Mechanism of How Social Contagion Inluences

Physicians' Prescription Decisions

None of the existing studies on physician social networks have tried to understand the
mechanism of how social contagion influences physicians' prescription decisions.
Does the follower just do what the opinion leaders do? For example, the follower
prescribes the same drug as the opinion leader does in all the existing literature dis-
cussed here. Or does the opinion leader's prescription behavior help the follower to
learn about the efficacy of the drug by reducing the uncertainty of the drug? Depending
on which mechanism is at work, the results would have different implications. If it is
the latter, the reduction of uncertainty through social network could be different from
the uncertainty reduction through detailing or prescription experiences.

15.5.5 Hierarchy and Variety in Physician Opinion Leaders

The physician opinion leaders have been classified by Stremersch and Van Dyke
( 2009 ) as “Clinical Leaders” (more academic and well known at the national level)
and “Market leaders” (regional opinion leaders affecting physicians through the