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.