Clinical and Financial Outcomes Associated With a Proton Pump Inhibitor Prior-Authorization Program in a Medicaid Population

Objective: To examine the clinical and financial outcomes associated with a proton pump inhibitor (PPI) prior-authorization policy. Study Design: Interrupted time-series analyses of antisecretory prescription drug claims. Separate 6-month retrospective cohort analyses were conducted to estimate the clinical and financial effects of the policy. Patients and Methods: More than 1.2 million Medicaid enrollees, with subgroup analyses of 5965 continuously eligible, potential antisecretory medication users. Measures included antisecretory drug expenditures, proportions of patients with at least 1 gastrointestinal diagnosis and gastrointestinal-related ambulatory and inpatient medical service visit, and subsequent gastrointestinal-related and total medical service expenditures. Results: There was a 90.9% decrease in PPI per-member-permonth expenditures and a 223.2% increase in histamine 2 -receptor antagonist (H 2 A) per-member-per-month expenditures in the month immediately following the implementation of the policy (P < .001 for both). A greater proportion (80.7%) of prior-authorization eligible enrollees who received a PPI had at least 1 diagnosis for a gastrointestinal condition than enrollees who received an H 2 A (64.1%) or no antisecretory drugs (48.4%) (P < .001 for both). Twopart, finite mixture regression analyses indicated that the enrollees who received an H 2 A or no antisecretory drugs were no more likely to have incurred greater total medical care expenditures than enrollees who received a PPI. Conclusion: Prior authorization for PPIs had the effect of reducing use of high-cost PPIs, while encouraging use of lower costing H 2 As without evidence of adverse medical consequences. (Am J Manag Care. 2005;11:29-36)