Step therapy for antidepressants saves 11.7 percent in one year

Results of the implementation of a step therapy edit that required HMO members to use a generic antidepressant, excluding tricyclic antidepressants, before using a brand-name antidepressant resulted in drug cost savings of 11.7 percent for the entire class of antidepressants. That worked out to 36 cents per member per month.

The step therapy edit applied only to members with no claim history of antidepressant treatment for the preceding six months. These members were required to use a generic antidepressant. The $5-$10 copayment was waived for the first prescription. Preferred brand-name antidepressants were in tier 2, with a copayment of $20-$25 or coinsurance of 25 percent. Nonformulary brand antidepressants were in tier 3 of the formulary, with a copayment of $40-$45 or coinsurance of 50 percent. Findings were published in the Journal of Managed Care Pharmacy.

The researchers found that the dispensing rate for generic antidepressants increased by 20 percentage points (32.5 percent to 52.5 percent) in the intervention group, but only 7.4 percentage points (24.9 percent to 32.3 percent) in the comparison group (beneficiaries who were not subject to interventions involving antidepressant drug therapy in either 2004 or 2005). Antidepressant drug cost per day of therapy in the intervention group decreased by 11.7 percent in 2005, compared with the previous year. The control group saw a 2.7 percentage point decrease.

“Many MCOs have followed our lead in implementing generic step edits,” says Jeffrey D. Dunn, PharmD, MBA, formulary and contract manager at SelectHealth Plans (formerly IHC Health Plans) and lead author. He says the study only focuses on pharmacy costs, and further research is necessary to report about the associated medical costs.

Primary outcomes for the intervention group versus comparison group for antidepressants

Source: J Manag Care Pharm 2006;12(4):294-302