Ultimately, a pharmaceutical agent can only be used as often as physicians are willing to prescribe it. Therefore, physician preferences, perceptions, and prescribing habits play a significant role in determining the extent to which a new technology is utilized in the health care system. Factors that influence physician preference, perceptions, and prescribing habits include awareness of newer agents, the length of time an agent as been on the market, the clinical profile of the agents, and the physician's education or treatment philosophy.
Physicians may be influenced somewhat by the publication of treatment guidelines. These may either come from a nationally recognized expert source, such as the American Psychiatric Association, or may be produced in-house by a health plan. These guidelines may play a role in influencing physician-prescribing decisions to a greater or lesser degree.