The impact of proton pump inhibitor compliance on health-care resource utilization and costs in patients with gastroesophageal reflux disease

Abstract

Objective: Standard pharmacotherapy for patients with gastroesophageal reflux disease (GERD) includes treatment with proton pump inhibitors (PPIs). This study examined the effect of GERD patients' compliance with PPI therapy on health-care resource utilization and costs. Methods: This was a retrospective study of more than 25 million managed care lives in the United States from January 2000 through February 2005. Administrative claims data were obtained from the National Managed Care Benchmarks database, developed by Integrated Health Care Information Solutions. GERD-diagnosed patients who had at least two PPI dispensings were extracted and grouped into two treatment categories based on their PPI medication possession ratio (MPR): compliant (MPR > 0.8) and noncompliant. A regression-based difference-in-differences approach was used to estimate the effect of compliance on the frequency and costs of inpatient and outpatient visits and pharmacy costs. Statistical controls included health plan type, patient age, baseline use of nonsteroidal antiinflammatory drugs, and comorbidities. Results: Of the total 41,837 patients studied, 68% were compliant. On an annual, per-patient basis, PPI compliance resulted in 0.47 fewer outpatient visits (P = 0.040), 0.03 fewer inpatient visits (P = 0.015), and 0.47 fewer hospitalization days (P = 0.001) from the pre-PPI use period, compared to noncompliance. PPI therapy increased pharmacy costs for both groups, but the total annual health-care costs were reduced for both groups. Compliant patients experienced a greater decline in total cost from the pre-PPI period compared to noncompliant patients (declines of $3261 vs. $2406 per patient per year, P = 0.012). Conclusions: Both health-care resource use and costs were reduced after initiation of PPI therapy. Additional reductions from the pre-PPI period were further observed by compliance with PPI therapy. © 2008, International Society for Pharmacoeconomics and Outcomes Research (ISPOR).