This literature review highlights a litany of issues surrounding Medicaid preferred drug lists and their impact on quality and cost of care.  The number and magnitude of the issues lead the authors to urge additional research on both the short and long term effects of prescription drug lists. 

Ovsag, K., Hydery, S., & Mousa, S. A. (2008).  Preferred drug lists: potential impact on healthcare economics. Vascular Health and Risk Management, 4(2): 403-13. http://www.ncbi.nlm.nih.gov/pubmed/18561515

Authors: Kimberly Ovsag, Sabrina Hydery, Shaker A. Mousa