Patients should be advised never to stop aspirin unless explicitly told to do so Is aspirin (acetylsalicylic acid) the wonder drug it is purported to be? It prevents atherothrombotic cardiovascular events, colorectal cancer, and venous thromboembolism and is cheap, effective, and safe.1 2 3 It has even been claimed that all elderly people should receive low dose aspirin plus other cardioprotective agents blended into a suitable polypill.4 The drawbacks are that the effects of aspirin vary greatly between individuals,5 and its role in the primary prevention of cardiovascular disease (in those without a clinical history of cardiovascular disease) has been challenged in several subsets of patients, including those with diabetes and peripheral artery disease.1 So what happens when aspirin is discontinued in patients with existing cardiovascular disease?6 In the linked case-control study (doi:10.1136/bmj.d4094), Garcia Rodriguez and colleagues assess the effect of withdrawal of low dose (75-300 mg/day) aspirin in UK general practice when it has originally been prescribed for …