A therapeutic substitution policy for proton pump inhibitors: clinical and economic consequences.
OBJECTIVE
With the growing need to provide prescription drug benefits to older patients and to contain costs, it will be necessary to direct that coverage so as to make expenditures as efficient as possible. We evaluated the clinical and economic consequences of coverage restriction for 3 leading proton pump inhibitors (PPIs) in a large-scale natural experiment.


METHODS
The study design was a time-trend analysis in the setting of a provincial drug benefits program in British Columbia, Canada. We studied all British Columbia residents aged 66 or older (N = 501,104) using linked data on all prescription drug dispensings, physician services, and hospitalizations between January 2002 and June 2004. The new policy restricted coverage to rabeprazole and required treatment failure with a histamine H2 blocker. More widely used PPIs (omeprazole, pantoprazole, and lansoprazole) had to be paid for out of pocket, unless the physician requested an exemption. The main outcome measures were utilization of PPIs, drug discontinuation rates, gastrointestinal hemorrhage rates, and drug expenditures.


RESULTS
Utilization of the restricted PPIs declined sharply after the policy change (-14,850 daily doses per month per 10,000 residents, P < .0001), whereas use of the covered PPI increased sharply (+19,300, P < .0001), with 45% of all PPI users switching to the covered agent within 6 months. We found no increased use of H2 blockers or stopping of gastroprotective drugs. There was no increase in the monthly rate of hospitalization for gastrointestinal hemorrhage after the PPI restriction (P = .35) even though the study had the power to detect increases of 24 events per 10,000 residents with 95% confidence. There was a slight increase in physician visits 3 months after the policy change (P = .01) for a 2-month period when 9% of new rabeprazole users were switched back to a restricted PPI. In the first 6 months of the policy change, the provincial health plan saved at least 2.9 million Canadian dollars as a result of the policy change.


CONCLUSIONS
Coverage restriction of 3 leading PPIs led to substantial utilization changes and savings, without increased noncompliance or clinical complication.
Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02120, USA. schneeweiss@post.harvard.edu
Sebastian
S
Schneeweiss
Malcolm
M
Maclure
Colin R
CR
Dormuth
Robert J
RJ
Glynn
Claire
C
Canning
Jerry
J
Avorn
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000368:Aged; D000369:Aged, 80 and over; D000897:Anti-Ulcer Agents / Q000191:economics* / Q000600:supply & distribution*; D001562:Benzimidazoles / Q000191:economics* / Q000600:supply & distribution*; D001955:British Columbia; D017046:Cost Savings; D016208:Databases, Factual / Q000706:statistics & numerical data; D017723:Drug Utilization Review; D005260:Female; D006299:Health Services for the Aged / Q000191:economics / Q000706:statistics & numerical data; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007356:Insurance, Pharmaceutical Services / Q000191:economics*; D064747:Lansoprazole; D008297:Male; D009853:Omeprazole / Q000031:analogs & derivatives* / Q000191:economics / Q000600:supply & distribution; D000077402:Pantoprazole; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D064750:Rabeprazole; D013454:Sulfoxides / Q000191:economics / Q000600:supply & distribution
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D001562:Benzimidazoles; D013454:Sulfoxides; D064747:Lansoprazole; D064750:Rabeprazole; D000077402:Pantoprazole; D009853:Omeprazole