The top 20 percent of endocrinologists, who wrote prescriptions for oral diabetes therapies from September 2007 through August of this year, were responsible for 95 percent of new-to-brand prescriptions in that specialty, specifically, new product starts, add-on therapy, or product switches, according to a report from SDI, a healthcare data research firm.

By contrast, the top 20 percent of primary care prescribers were accountable for 78 percent of new-to-brand oral diabetes prescriptions, the report said. In the case of primary care prescribers, prescription writing for oral diabetes medications was more diffuse. The top 30 percent of prescribers were accountable for 90 percent of new-to-brand prescriptions in the group.

SDI said that identifying which prescribers write a high number of new-to-brand prescriptions is significant because these prescribers are the key drivers of market growth. The traditional method of evaluating prescribers based on total prescriptions, which include renewals and refills, does not accurately identify customer segments that have the most influence on generating new market volume.

Based on the example above, SDI predicted that a company could target just 20 percent of the top endocrinologists to reach those driving the prescriptions that represent true new business. For primary care, they would need to target the top 30 percent of prescribers.