Aspirin Less Costly than No Treatment; Proton Pump Inhibitors Not Cost-Effective

A new cost-utility analysis investigating the use of aspirin and proton pump inhibitors (PPIs) in coronary heart disease (CHD) prevention found that treatment with aspirin was less costly and more effective than no treatment at all for middle-aged men across a wide range of CHD and gastrointestinal (GI) tract bleeding risk factors; however, adding a PPI was cost-prohibitive for those with an average GI bleeding risk. The results of the study were recently published in the Archives of Internal Medicine [2011;171(3):218-225]. Previous research has shown that aspirin reduces nonfatal myocardial infarction; however, it has also been shown to increase GI bleeding. To reduce this bleeding, PPIs can often be used, but this is an additional cost and it is not clear whether the addition of PPIs is cost-effective in CHD prevention. In this study, researchers performed a cost-utility analysis to examine the effectiveness of low-dose aspirin with and without the use of a PPI for CHD prevention in men with a range of CHD and upper GI bleeding risks. Researchers used a Markov model to compare the costs of 3 groups: no treatment, 81 mg/day of generic aspirin, and aspirin plus 20 mg/day of generic omeprazole. Those in the base-case analysis were assumed to be 45-year-old healthy men with no history of CHD events and a 10% 10-year CHD risk. Researchers examined scenarios for men aged 45, 55, and 65 years with ≤6 different risk levels. It was assumed that aspirin reduced nonfatal myocardial infarction by 30%, but it also increased total stroke by 6% and doubled the GI bleeding risk. It was also assumed that a PPI would reduce upper GI bleeding by 80%. Researchers used an annual aspirin cost figure of $13.99 and a generic PPI cost of $200. The outcomes in the study included costs, total costs, patient survival in life-years, quality-adjusted life-years (QALYs), the incremental cost per QALY gained, and the number of myocardial infarctions, strokes, and GI bleeding events. After completing the analysis, researchers found that taking aspirin was more effective and less costly than no treatment at all for the base-case 45-year-old with a 0.8 per 1000 annual GI bleeding risk. According to the results, aspirin was associated with a cost of $17,571 and 18.67 QALYs, whereas the group receiving no treatment was associated with a cost of $18,483 and 18.44 QALYs. Adding the PPI to treatment increased the QALYs to 18.68 but was more costly ($21,037). When comparing the figures from the aspirin-alone group to the aspirin plus PPI group, researchers found an incremental cost per QALY of $447,077 for the aspirin plus PPI group. However, the incremental cost per QALY is decreased to <$50,000 when the annual GI bleeding risk is 4 in 1000 and is considered cost-saving compared with aspirin alone when the GI bleeding risk is >7 in 1000. Researchers found similar results for the 55- and 65-year-old men. They concluded that aspirin alone was more effective and less costly than no treatment at all in preventing CHD, but the use of a PPI was cost-prohibitive unless the patient had a greater GI bleeding risk. They acknowledged several study limitations. These included only using data on upper GI bleeding, estimating the benefit of PPIs based on results from a single trial, and not including the risk of other possible adverse clinical outcomes in the model.