Abstract
Background: To limit quickly rising prescription drug expenditures, many state Medicaid programmes have implemented preferred drug lists (PDLs) and prior authorisation (PA). Lessons from Medicaid efforts may be informative for Medicare, which started covering outpatient prescription drugs recently.
Objectives: To examine how the cost of compliance with Medicaid PDLs for antihypertensives and statins varied across physicians, and to assess the effects of PDLs on physician prescribing patterns and access for Medicaid patients.
Data and methods: An anonymous survey of primary care physicians and cardiologists in nine states with PDLs was conducted in December 2005 and January 2006. Survey responses were augmented with physician prescribing data, practice location characteristics, and publicly available information about state PDLs. We analysed six physician-level outcome measures: annual PDL-related costs; the proportion of Medicaid prescriptions covered by the PDL; the proportion of Medicaid prescriptions written for an alternative to a physician’s most preferred drug because of PDLs; the proportion of times no drug was prescribed to a Medicaid patient because of PDLs; whether they restricted their new Medicaid patient caseload because of PDLs; and whether they decreased the proportion of prescriptions not covered by the Medicaid PDL for non-Medicaid patients. We assessed how these outcomes varied with Medicaid caseload, physician practice size, and socioeconomic characteristics of the practice’s ZIP Code.
Results: Costs from complying with Medicaid PDLs for statins and antihypertensives were greatest for physicians in solo practices with high Medicaid caseloads located in poor areas. Although all physicians’ prescribing patterns were influenced to some extent by PDLs, those with high volumes of Medicaid prescriptions were affected more. They more frequently prescribed Medicaid patients a less-preferred medication or nothing at all, and were more likely to alter their prescribing to non-Medicaid patients. Physicians with low Medicaid prescription volumes in areas with fewer minorities were more likely to limit their willingness to treat new Medicaid patients.
Conclusion: The burden of Medicaid PDLs fell greatest on physicians in disadvantaged areas and their patients.
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References
Centers for Medicare and Medicaid Services. 2004 Medicaid managed care enrollment report [online]. Available from URL: http://www.cms.hhs.gov/MedicaidDataSourcesGenInfo/downloads/mmcer04.pdf [Accessed 2006 October 27].
Centers for Medicare and Medicaid Services. National health expenditures by type of service and source of funds: calendar years 2004–1960 [online]. Available from URL: http://www.cms.hhs.gov/NationalHealthExpendData/02_NationalHealthAccountsHistorical.asp [Accessed 2006 October 27].
Smith C, Cowan C, Heftier S, et al. National health spending in 2004: recent slowdown led by prescription drug spending. Health Aff 2006; 25(1): 186–96
Center for Medicaid and State Operations. 2004. Letter to state Medicaid directors September 9, 2004. [online] Available from URL: http://www.nasmd.org/Multi-State-pool-letter.pdf [Accessed 2006 October 27].
MacKinnon NJ, Kumar R. Prior authorization programs: a critical review of the literature. J Manag Care Pharm 2001; 74: 297–303
Fischer MA, Schneeweis S, Avorn J, et al. Medicaid prior-authorization programs and the use of cyclooxygenase-2 inhibitors. N Engl J Med 2004; 351: 2187–94
Bukstein DA, Cheriayil GA, Gepner AD, et al. The economic burden associated with prior authorizations in an allergist office. Allergy Asthma Proc 2006; 27(2): 119–22
Soumerai SB. Benefits and risks of increasing restrictions on access to costly drugs in Medicaid. Health Aff 2004 Jan/Feb; 23(1): 135–46
Headen A, Masia N. Exploring the potential link between Medicaid access restrictions, physician location, and health disparities. Am J Manag Care 2005; 11: SP21–26
Cunningham PJ. Medicaid cost containment and access to prescription drugs. Health Aff 2005; 24(3): 780–9
Sloan F, Mitchell J, Cromwell J. Physician participation in state Medicaid programs. J Hum Resourc 1978; 13 Suppl.: 211–245
Adams K. Factors affecting physician preventive care to Medicaid children. Health Care Financ Rev 2001; 22(4): 9–26
Perloff JD, Kletke P, Fossett JW. Which physicians limit their Medicaid participation and why. Health Serv Res 2006; 30(1): 7–26
Glied S, Zivin JG. How do doctors behave when some (but not all) of their patients are in managed care? J Health Econ 2001; 21: 337–53
Wang YR, Pauly MV, Lin YA. Impact of Maine’s Medicaid drug formulary change on non-Medicaid markets: spillover effects of a restrictive drug formulary. Am J Manag Care 2003; 9: 686–96
Wang YR, Pauly MV. Spillover effects of restrictive drug formularies on physician prescribing behavior: evidence from Medicaid. J Econ Manag Strat 2005; 14(3): 755–73
Virabhak S, Shinogle JA. Physicians’ prescribing responses to a restricted formulary: the impact of Medicaid preferred drug lists in Illinois and Louisiana. Am J Manag Care 2005; 11: SP14–20
Fossett JW, Peterson JA. Physician supply and Medicaid participation. Med Care 1989; 27(4): 386–96
Polsky D, Kletke PR, Wozniak GD, Escarce JJ. HMO penetration and the geographic mobility of practicing physicians. J Health Econ 2000; 19(5): 793–809
Centers for Medicare and Medicaid Services. 2006 Medicare trustees report [online]. Available from URL: http://www.cms.hhs.gov/apps/media/press/release.asp?Counter=1846 [Accessed 2006 October 27]
Hoadley JE, Hargrave E, Cubanski J, et al. An in-depth examination of formularies and other features of Medicare drug plans, Kaiser Family Foundation. Available from URL: http://www.kff.org/medicare/upload/7489.pdf [Accessed 2006 October 27]
Murawski MM, Abdelgawad T. Exploration of the impact of preferred drug lists on hospital and physician visits and the costs to Medicaid. Am J Manag Care 2005; 11: SP35–42
Smalley WE, Griffen MR, Fought RL, et al. Effect of a prior-authorization requirement on the use of nonsteroidal anti-inflammatory drugs by Medicaid patients. New Engl J Med 1995; 332: 1612–17
Wilson J, Axelsen K, Tang S. PDL implementation increases chances that Medicaid patients discontinue filling prescriptions for antihypertensives. Am J Manag Care 2005; 11: SP27–34
Särndal CE, Swensson B, Wretman J. Model assisted survey sampling. New York: Springer-Verlag, 1992
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Ketcham, J.D., Epstein, A.J. Which Physicians are Affected Most by Medicaid Preferred Drug Lists for Statins and Antihypertensives?. PharmacoEconomics 24 (Suppl 3), 27–40 (2006). https://doi.org/10.2165/00019053-200624003-00003
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DOI: https://doi.org/10.2165/00019053-200624003-00003