OBJECTIVES: Aspirin prevents myocardial infarction (MI), but increases gastrointestinal bleeding (GIB) and dyspepsia. Proton pump inhibitors (PPIs) reduce GIB risk and dyspepsia, but economic implications of use with aspirin has not been studied. We examine cost-utility of low-dose aspirin + PPI (omeprazole) 20 mg daily; low-dose aspirin alone; or no therapy for primary cardiovascular (CVD) prevention.
METHODS: We develop a Markov model and performed a lifetime analysis of middle-aged and older men without history of CVD at levels of 10-year risk for coronary heart disease (CHD) events from 2.5% to 25%, using a third-party payer perspective. Baseline risks of MI, stroke, and CHD death were estimated from Framingham equations. Baseline risks of GIB and dyspepsia were estimated from cohort studies. Non-cardiovascular mortality obtained from US life tables. From systematic reviews, aspirin reduced CHD events by 30%, increased total stroke risk by 6%, increase risk of dyspepsia by 80%, and increase risk of GIB 2-fold for patients without history of GIB and 10-fold for patients with history of GIB. Addition of PPI reduced GIB risk by 90% and dyspepsia by 50%.
RESULTS: For the base case of 45-year-old men with 10-year risk for CHD events of 10%, aspirin alone was more effective and less costly than no treatment. Aspirin + PPI (compared with aspirin alone) had cost/QALY of $473,673 when dyspepsia is not modeled and $51,059 when the effects of treating dyspepsia are included. The incremental cost/QALY of adding PPI was found to improve as CHD or GIB risk increases.
CONCLUSIONS: Aspirin for CHD prevention is cost-saving in men over 45 with a 10-year CHD risk of 10% or greater. When the benefits from treating dyspepsia are not included, adding PPI is not cost-effective as a routine means of preventing GI bleeding. The cost-effectiveness of adding PPI to aspirin is dependent on PPI cost and protective effect against GI adverse events.
