Pharmacy Record Registration of Acetyl Salicylic Acid (ASA) Prescriptions in Quebec

Abstract

To determine the extent of which acetyl salicylic acid (ASA) use is included in patients' pharmacy records. During an in-home interview, people aged ≥ 65 years were asked to report all of the medications they had used at least once, including over-the-counter drugs, during the preceding month. Researchers recorded information on the drug name, reason for its use, and whether a physician prescribed it. From the pharmacy records, the drug names, prescription fill dates, quantities supplied, and the numbers of days' supply were recorded. The level of agreement for ASA use across data sources was assessed using proportions of agreement and kappa coefficients. Of 193 individuals interviewed, 86 reported the use of ASA, including 76 ASA users (88.4%) who said it was prescribed by a physician. Pharmacy medication records indicated that there were 74 users of ASA. The proportion of agreement for ASA use was 93.8%, and kappa coefficient was 0.87 (95% confidence interval: 0.80-0.94). The sensitivity, specificity, and positive predictive value of the pharmacy data were all high. A large proportion of ASA use is documented in pharmacy records in Quebec. Thus, the information regarding ASA use in pharmacy records is reliable. This result may not be reproducible in other settings where pharmaceutical reimbursement rules are different.