Effects of Medicaid Access Restrictions on Statin Utilisation for Patients Treated by Physicians Practising in Poor and Minority Neighbourhoods

Objectives: To explore whether Medicaid preferred drug lists (PDL) impact the utilisation of restricted statin (cholesterol-reducing) medication for all Medicaid patients equally or disproportionately impact patients who are treated by doctors prescribing in poor or minority neighbourhoods. Study design: A retrospective, regression-based analysis, using a pharmacy claims database combined with demographic variables derived from census for the zip code of the practising physician. Methods: Changes in the proportion of statin prescriptions filled for off-PDL (restricted) medicines before and after the adoption of a Medicaid PDL were examined in six states (Alabama, Florida, Georgia, Texas, Virginia, West Virginia). Two non-PDL states were used as controls for underlying market dynamics (New York, North Carolina). Demographics of physicians’ neighbourhoods (poverty and ethnicity) were used to examine the variation in prescribing based on the characteristics of physicians’ areas of practice. Results: The decline in the use of restricted prescriptions (off-PDL drugs) after a PDL varied considerably from state to state, with the greatest decline in Florida (97%) and the smallest decline in Texas (65%). There was a statistically significant and positive association between the degree of decline in the use of restricted medications and the share of impoverished households and the share of the minority population in Alabama, Florida and Texas. Conclusion: The analysis indicates that there is considerable variation in the impact of a preferred drug list by state, and that in certain states the prescriptions filled after a PDL adhere more closely to Medicaid-imposed restrictions in poorer or more ethnically diverse neighbourhoods. This could imply that because of the PDL, in these poorer and more ethnically diverse neighbourhoods, there is a greater change in physicians’ prescribing practice, fewer patients receive the restricted medication by prior authorisation, and more patients experience a disruption in their medication regimen and any resultant unintended consequences. This is an area worthy of future exploration, particularly as the oldest and most vulnerable of these patients transition into Medicare part D for their prescription coverage and may experience changes in formulary. Copyright Adis Data Information BV 2006