Formulary access using a PDA-based drug reference tool: does it affect prescribing behavior?

We assessed the association between formulary access via a handheld drug reference tool and utilization of generic (Tier 1) and non-generic, non-formulary (Tier 3) medications. In a retrospective before-after study of physician prescribing behavior for patients in a large, national health plan, physicians with formulary access using Epocrates(TM) showed smaller (0.5%) increases in Tier 3 prescribing over time compared to physicians without such access.