Impact of proton pump inhibitor utilization patterns on gastroesophageal reflux disease-related costs.

OBJECTIVE

To determine proton pump inhibitor (PPI) treatment patterns and their effect on costs related to gastroesophageal reflux disease.

METHODS

This study used claims data to identify continuously enrolled subjects diagnosed with gastroesophageal reflux disease (GERD) and newly treated with a PPI between Oct. 1, 1999 and March 31, 2000. Data were analyzed for 6 months following PPI initiation. Results were stratified by first PPI filled during the study period. Compliance (as measured by a medication-possession ratio), dosage escalation (> 25 percent of initial dose), and daily average consumption (DACON) were measured. Regression analysis was performed on GERD-related costs using treatment patterns, type of PPI drug, and compliance as independent variables of interest.

RESULTS

Of 75,452 subjects, there were 51,232 (67.9 percent) lansoprazole, 22,829 (30.3 percent) omeprazole, and 1,391 (1.8 percent) rabeprazole subjects. The possession ratio was not significantly different by drug. Only 3.5 percent of rabeprazole subjects escalated versus 5.5 percent of omeprazole subjects and 9.3 percent of lansoprazole subjects (p = .0001). Among subjects with esophageal ulcer or hiatal hernia, rabeprazole users had a significantly lower final DACON (1.03) versus both lansoprazole (1.20) and omeprazole subjects (1.22, p = .0299). Subjects who were compliant with therapy (ratio > 0.80) had 43 percent higher GERD-related pharmacy costs and 33 percent higher GERD-related total costs (both p < .001). GERD-related medical costs were not significantly affected by compliance. Subjects who filled lansoprazole prescriptions had 9.4 percent higher GERD-related pharmacy costs versus rabeprazole subjects (p < .01). Omeprazole subjects had 12.5 percent higher GERD-related total costs versus rabeprazole subjects (p < .01), while lansoprazole subjects had 18 percent higher GERD-related total costs versus rabeprazole subjects (p < .001).

CONCLUSIONS

Rabeprazole subjects had lower GERD-related costs, less escalation, and lower DACON (measured as number of tablets consumed per day), compared to lansoprazole and omeprazole subjects. Compliance was not significantly different between the drugs, nor did increased compliance decrease GERD-related costs.