Predictors and time trends in clopidogrel and proton pump inhibitor coprescription with low‐dose acetylsalicylic acid

PURPOSE: To determine trends and predictors of clopidogrel and proton pump inhibitor (PPI) coprescription with low-dose acetylsalicylic acid (ASA) prescribed for secondary cardiovascular or cerebrovascular disease (CVD) prevention in UK primary care. METHODS: Patients aged 50-84 years who received a first prescription for low-dose ASA for secondary CVD prevention in 2000-2001 (n = 10,330) or 2006-2007 (n = 8154) were identified in The Health Improvement Network UK primary care database. Clopidogrel or PPI coprescriptions received within 15 days after the first low-dose ASA prescription were ascertained. RESULTS: Clopidogrel coprescription with low-dose ASA increased from 1.6% to 25.2% between the two study periods; PPI coprescription increased from 11.6% to 28.3%. Low-dose ASA indications of myocardial infarction [odds ratio (OR) 11.7, 95% confidence interval (CI) 10.2 to 13.4] and unstable angina (OR 1.73, 95%CI 1.09 to 2.75) were positive predictors of clopidogrel coprescription in 2006-2007, relative to chronic ischaemic heart disease. Patients at high risk of upper gastrointestinal bleeding were more likely to receive a PPI than those at lower risk in 2006-2007 (OR 4.36, 95%CI 3.93 to 4.84). In this period, 65.5% of patients who required a clopidogrel coprescription according to guideline recommendations received one, and 44.3% of patients at high risk of upper gastrointestinal bleeding received a PPI. CONCLUSION: Clopidogrel and PPI coprescription with low-dose ASA increased markedly between 2000-2001 and 2006-2007; however, many patients on low-dose ASA did not receive the recommended coprescriptions at the end of the study period.