Determining proton pump inhibitor prescription dispensing patterns and adherence to STOPP criteria for Nova Scotia Seniors Pharmacare Program beneficiaries

Background Proton pump inhibitors (PPIs) are often prescribed potentially inappropriately. The screening tool of older person's potentially inappropriate prescriptions (STOPP) for therapeutic dose PPIs has been adapted to examine PPI discontinuation, dose reduction, or switching to Histamine-2 Receptor Antagonist (H2RA) after 60 days. Objectives The objectives of the present study were to (1) describe the use of acid suppression therapy (PPIs and H2RAs) 60 and 90 days after a new PPI dispensing, (2) assess predictors of lack of adherence to adapted STOPP criteria for PPI use, and (3) assess PPI dispensing over time. Methods This was a retrospective cohort study of beneficiaries of the Nova Scotia Seniors Pharmacare (NSSP) aged 66 years or older who were newly dispensed a PPI between January 1, 1997 and March 31, 2011. The main outcome measure was adherence to the adapted STOPP criteria, which was analyzed using logistic regression. Results A total of 14,453 participants were included: 89.8% beginning on standard dose and 10.2% beginning on high-dose PPI. Of those beginning on high-dose PPI, 26.4% were dispensed high-dose PPI at day 60 and 30.2% were dispensed high-dose PPI at day 90. Predictors of lack of adherence to our adapted STOPP criteria included age >= 86 years, rural residence, and hospitalization within 1 year prior to cohort entry. Conclusions Many PPI prescriptions dispensed for NSSP beneficiaries fail to adhere to the STOPP criteria. Predictors of lack of adherence to the adapted STOPP criteria were identified.