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Factors that affect formulary switching

MANAGED CARE January 2008. © MediMedia USA
The Formulary Files

Factors that affect formulary switching

MANAGED CARE January 2008. ©MediMedia USA













New research from Express Scripts provides some important insights into the role of patient characteristics and plan design factors when it comes to getting members to switch to lower-tiered agents after a formulary status change. Of the patient-related factors that affected switching, being female, prior statin switching experience, and member outreach to the pharmacy benefit manager consistently and positively influenced switching. Step therapy, brand preferred/nonpreferred copayment differences, and receipt of a response letter alerting the member to the switch positively influenced switching.

Compared to members with a brand preferred/nonpreferred copayment difference of less than $16, members with copayment differences of $16–$30, $31–$40, and $41 and higher were more likely to switch to a preferred agent (20 percent, 23 percent, and 59 percent of the time, respectively). Ellen Cox, director of research at Express Scripts, says, “There is a basic fundamental — the greater the price differential, the more likely the member will switch. That doesn’t mean that the plan makes the branded product financially burdensome; it could reduce the cost of the generic to create that price differential.”

Source: Cox ER, et al. 2007. Ann Pharmacother.41;1946–1953.