Letter by Klein Regarding Article, "Evaluation of Dose-Related Effects of Aspirin on Platelet Function: Results From the Aspirin-Induced Platelet Effect (ASPECT) Study"

A few issues are worthmentioning.The overall compliance rate for daily aspirin therapy was stated tobe 98%. For this 3-period/3-treatment arm crossover long-termoutpatient study, the almost ideal adherence to aspirin that wasachievedisdifferentthanthatfrommanypreviouslyreportedclinicalstudies. It is well-established that lack of compliance represents thelargest practical obstacle for the success of antiplatelet therapy,particularly for aspirin. Minor bleeding events result in unreportedwithdrawal from antiplatelet medication. These adverse events can-not be avoided in studies designed like the ASPECT study. A recentmeta-analysis of 10 antiplatelet prevention studies suggested that therange of noncompliance is 12% to 52% in all patients, with only 3%to 21% due to drug-induced adverse events.