Aspirin without PPI cost-effective despite small bleeding risk

Despite the risk of gastrointestinal bleeding, low-dose aspirin is cost-effective for primary prevention of coronary heart disease in many middle-aged men, and the addition of a proton-pump inhibitor (PPI) does not add significant benefit, a new study found.

Researchers used a Markov model to compare costs and outcomes associated with low-dose aspirin alone, aspirin with a PPI (omeprazole, 20 mg/d), or no medication for coronary heart disease (CHD) prevention in men over 45 years old. Overall, in the studied population, aspirin reduced nonfatal myocardial infarctions by 30%, increased stroke by 6% and doubled the risk of gastrointestinal (GI) bleeding. The results were published in the Feb. 14 Archives of Internal Medicine.

According to the model, a 45-year-old man with a 10-year CHD risk of 10% and 0.8 per 1,000 annual GI bleeding risk would have lower medical costs and more quality-adjusted life-years (QALYs) if he took aspirin alone instead of no treatment ($17,571 and 18.67 QALYs vs. $18,483 and 18.44 QALYs). However, adding a PPI (which researchers assumed to cost $200 per year) significantly increased the cost per QALY—to $21,037 and 18.68, an incremental cost per QALY of $447,077. Models of risk for 55-year-old and 65-year-old men found similar results.

Preventive use of PPIs would be cost-effective in men who have a higher than average risk of bleeding, the modeling study found. If a 45-year-old man had a GI bleeding risk of 5 per 1,000 (about four times the typical risk), adding a PPI to aspirin for $200 per year would have a favorable cost-effectiveness ratio of $22,000 per QALY gained. However, if the PPI cost is that of a branded drug ($1,951 per year), the bleeding risk would have to 6.7 per 1,000 to make the drug cost-effective.

Based on these findings, the researchers concluded that aspirin is cost-effective as primary prevention in middle-aged men with a range of CHD and GI bleeding risks, and its benefits are only outweighed by the risks of GI bleeding in men with high existing risk, such as those who have had previous bleeds. The addition of PPI therapy to an aspirin regimen is not cost-effective for patients at low or medium bleeding risk, but may be valuable for men who have a risk of more than 4 per 1,000 per year, the study found. Clinicians should assess patients' risk of GI bleeding by considering age, GI bleeding history, and use of other medications that increase bleeding risk, the study authors recommended.