Physicians who meet with pharmaceutical sales reps less frequently – or who do not meet with them at all — are much slower to drop medications with the FDA’s “black box” warnings and to adopt first-in-class therapies.

That’s according to results of a long-term, multi-event study study published in the Journal of Clinical Hypertension and the subject of an article in PharmaLive.

According to the study, doctors whose access to pharma sales reps is limited would take more than four times longer to change prescribing habits based on new information than their peers who had more frequent contact.

The study, entitled “Can Access Limits of Sales Representatives to Physicians Affect Clinical Prescription Decisions? A Study of Recent Events with Diabetes and Lipid Drugs,” studied prescriptions written by 58,000-72,000 primary care physicians and specialists as they wrote prescriptions around a first-in-class new drug launch, a newly imposed black box warning, and the report of perceived negative clinical trial outcomes data.

Conducted by Temple University’s Fox School of Business and ZS Associates, a global sales and marketing consulting firm with a deep presence in the pharmaceutical industry, “The study analyzed for the first time, and on a large scale, what happens to physicians’ prescriptions when you decrease access that pharmaceutical sales reps have to doctors,” said George Chressanthis, professor of healthcare management and marketing at Temple, and lead on this study. He began monitoring primary care and specialist physician data in 2008.

Pratap Khedkar, co-author of the study, says the findings suggest that doctors should seek to balance their information sources and that denying sales reps access to doctors “can result in serious information gaps.” Sales reps, he continues, “do help physician stay current on therapy developments.”

Our friend Dr. Richard Vanderveer recently blogged about this post and offered a different interpretation of the data. According to Dr. Vanderveer, doctors who see reps are likely to have their prescribing habits influenced by them. This is no surprise and is the reason exactly why HMOs, ACOs, and managed care organizations want to limit access to reps – they want to make sure MDs prescribe the drugs they’ve put on their formularies.

“Physicians who see reps get their prescribing confidence from doing what everyone else is doing,” writes Dr. Vanderveer.

The doctors that aren’t seeing reps – and their numbers are increasing daily – “march to a different drummer,” continues Dr. Vanderveer. “They consult less commercial, more academic sources of medical information. They actively communicate with other doctors in their practices to ensure standardization of treatment against key outcomes measures. They develop outcomes-based treatment protocols for key treatment areas. They are more likely to be purposeful and deliberate than blow in the wind.”

It would be interesting to see how this data would change if the doctors were receiving information via email instead of via rep visits. Especially if that information were targeted to physicians known as influencers to determine how the information would be disseminated among their peers.

The salesforce is, by necessity, becoming much more consultative — the way they used to be — but because there are fewer reps, pharmaceutical companies will need to find other ways to disseminate information, especially about new drugs and new research.