Esomeprazole formulary exclusion: impact on total health care services use and costs.

Esomeprazole was excluded from the United Healthcare formulary for all commercial health plan members January 1, 2007. A retrospective analysis of the Ingenix LabRx database (September 1, 2005, through June 30, 2007) evaluated the effect of this exclusion on health care utilization and costs in a real-world setting. Total medical care services, including pharmacy claims, were examined for 6 months before and after the esomeprazole exclusion. Patients aged ≥ 18 years were included if they had continuous health plan enrollment (September 1, 2005, through June 30, 2007), ≥ 1 esomeprazole prescription during the index period (March 1 through August 31, 2006), and ≥ 2 esomeprazole prescriptions (with no switch to another proton pump inhibitor [PPI]) during the baseline period (sliding 6-month window from September 1 through August 31, 2006). During the 6-month post-exclusion period (January 1 through June 30, 2007), 19.5% of patients remained on esomeprazole, 43% switched to another PPI, and 37.5% had no prescription PPI claims. Compared with the previous 6 months, post-exclusion was associated with increased health care utilization, including a 4.2% increase in number of inpatient visits, and a 2.7% increase in other services (eg, laboratory testing, ambulatory procedures). Esomeprazole prescriptions decreased by 76.5%, whereas overall pharmacy claims for all drug classes (including gastrointestinal drugs) increased by 5.2%. Six-month prescription drug costs decreased by $177/patient (95% confidence interval [CI], $160-$194/patient), whereas costs for total medical services increased by $450/patient (95% CI, $259-$640/patient), resulting in a net increase of $273/patient (95% CI, $137-$408/patient). Total and gastrointestinal-related medical services costs were significantly higher for those switching to another PPI versus those continuing esomeprazole. Inpatient utilization contributed most (44.5%) to increased costs of nongastrointestinal comorbidities. This study provides real-world evidence that formulary exclusions can lead to unintended increases in overall health care utilization and costs that exceed anticipated pharmacy budget savings.