When it comes to making decisions about including a medication on a drug list, Lisa A. Bero, PhD, a professor of clinical pharmacy and health at the University of California–San Francisco, says that “selection for any list — a formulary, an essential-medicines list, a preferred drug list, or a reimbursement list — should be made based on the most rigorous evidence of safety and efficacy.”
She and her colleagues compared state Medicaid preferred drug lists (PDLs) with the World Health Organization’s Essential Medicines List (EML), and found that only 6 of 120 agents on the EML appeared on fewer than 50 percent of PDLs — meaning that most PDLs listed the essential medicines.
However, many medicines appeared only on PDLs and not the EML. These medicines were less likely than EML agents to have generic versions available (56 percent vs. 76 percent) and less likely to be first-line treatments (21 percent vs. 41 percent).
The researchers noted a weak association between presence on the guidelines of the National Institute for Health and Clinical Excellence (NICE), which are developed using evidence-based methods, and PDL listing. This may indicate that clinical effectiveness is not a primary motivator for state PDL decisions. The researchers used the NICE guidelines because the United States does not publish national, standardized, evidence-based treatment guidelines.
Bero says that most PDLs “did seem to have the core medicines that corresponded with the EML, but outside of that, the variability became great. So there were a lot of nongeneric products. There were a lot of products that serve the same purpose in terms of treatment efficacy. That raises the question about the evidence base for putting those medicines on the list.” And that makes checking drug lists multiple times all the more important.
|These agents appear on only 1 preferred drug list |
|Eight medications were listed on only 1 PDL. None of these medicines was available as a generic formulation or recommended as a first-line treatment. “Why are these products on some PDLs instead of the more affordable, recommended products?” asks Lisa A. Bero, PhD. “They may be on the PDL because they are part of a ‘package deal’ of medicines. So they may be there for economic, not public health reasons.”|
|Eprosartan + HCTZ*||Antihypertensive||South Carolina|
|Aliskiren + valsartan||Antihypertensive||District of Columbia|
|*HCTZ = hydrochlorothiazide|
Source: Millar TP, Wong S, Odiema DH, Bero LA. Applying the essential medicines concept to U.S. preferred drug lists. Am J Public Health. 2011;101:1444–1448