Concordance between discharge prescriptions and insurance claims in post‐myocardial infarction patients

PURPOSE: To assess the degree of concordance between the information (drug quantity, days' supply, and daily dose) recorded on hospital discharge prescriptions and what appears in a public drug insurance electronic claims database. METHODS: A retrospective chart audit of hospital discharge prescriptions with linkage to a prescription claims database was conducted. Three hundred and forty-five post-myocardial infarction patients discharged from an Ontario university-affiliated teaching hospital were included. The percentage of linkable records with perfect agreement between the written prescription and the insurance claim was our measure of concordance. RESULTS: Seventy-seven per cent and 82% of discharge prescriptions were filled within 7 days, and 120 days post-discharge, respectively. Of those dispensed and that contained adequate information, concordance was perfect for days' supply, quantity, and daily dose for 70.7% (95%CI 67.9-73.4%), 65.9% (95%CI 63.2-68.7%), and 75.9% (95%CI 73.2-78.6%) of prescriptions, respectively. For cardiac drugs, which comprised the majority of filled prescriptions, concordance was greater for daily dose and days' supply than for quantity (75.7% [95%CI 72.7-78.6%] and 75.5% [95%CI 72.6-78.4%] vs. 65.3% [95%CI 62.3-68.4%]). Concordance varied by medication type. CONCLUSION: Most hospital discharge prescriptions were filled within 1 week. Among the data elements studied, concordance between written prescriptions and insurance claims was greatest for daily dose. Concordance was greater for scheduled cardiac medications than for other medications.