The Effect of Formulary Restrictions on Patient and Payer Outcomes: A Systematic Literature Review

BACKGROUND: Formulary restrictions are implemented to reduce pharmacy costs and ensure appropriate use of pharmaceutical products. As adoption of formulary restrictions increases with rising pharmacy costs, there is a need to better understand the potential effect of formulary restrictions on patient and payer outcomes. OBJECTIVE: To conduct a systematic literature review that assesses the effect of formulary restrictions on the following outcomes: medication adherence, clinical outcomes, treatment satisfaction, drug utilization, health care resource utilization, and economic outcomes. METHODS: Studies published in 2005 or later were identified from the MEDLINE, Embase, and Cochrane databases and the National Health Service Economic Evaluation Database, using 2 sets of search terms. A total of 17 formulary restriction terms (e.g., step therapy [ST] and prior authorization [PA]) and 55 outcome terms were included, resulting in 935 unique search term combinations. Two reviewers independently conducted analy...