In Berger et al.'s "Aspirin for the Primary Prevention of Cardiovascular Events in Women and Men," the researchers performed a meta-analytical review to determine whether or not there was a gender-based difference in the risks and advantages experienced when aspirin is used to treat cardiovascular disease.
In this study, a number of studies from the MEDLINE and Cochrane Central Register of Controlled Trials databases were analyzed, in addition to bibliographies of the selected trials and major scientific reports. The inclusion criteria included those studies which were randomized and controlled trials of aspirin therapy for those people who did not have cardiovascular disease; these studies also had to report data on aspects such as cardiovascular mortality, myocardial infarction and stroke, among others.
Great care was taken to extract and find the most appropriate studies for this review by the researchers; comprehensive search terms and bibliography searches yielded many different results for them, and personal contact with many of the researchers was performed in order to answer questions the researchers had about the data. After the 102 qualifying studies were identified, all but thirteen were excluded in order to find the randomized controlled trials. Seven were excluded which "did not report end points of interest, used aspirin as an adjunct to clopidogrel, were not primary prevention, or included duplicate results," leaving only six studies to work with (p. 307). Ideally, more studies could have been used, but the researchers were discerning enough in their methodology to determine the precise ones to use.
The researchers performed statistical analysis on the six studies using the Cochrane Q statistics in order to determine if the trials were heterogeneous, which turned out negative. The results of all the trials were combined and cumulative results were recorded. Between women and men 1285 and 2047 cardiovascular events occurred, respectively, and aspirin was shown to have a 12% and 14% risk reduction for cardiovascular events for women and men. Differences in aspirin effectiveness between men and women were theorized as occurring due to differences in aspirin metabolism between the sexes. However, some limitations include the lack of uniformity in the administration of aspirin between all of the studies, as well as women only showing up in 3 of the six studies, only 1 of which was women-only. Therefore, there may be a decided lack of data regarding women's reactions to aspirin as opposed to men.
According to the results of the study, aspiring therapy has been shown to definitively reduce the risk of cardiovascular disease among adults who already have a higher risk of getting it. However, the researchers were unable to determine if men and women derive the same level of prevention. Aspirin's ability to reduce the risk of ischemic stroke in women and myocardial infarction in men is cited as the primary reasons for its effectiveness in reducing cardiovascular events.
Berger, Jeffrey S., Roncaglioni, Maria C., Avanzini, Fausto, Pangrazzi, Ierta, Tognoni, Gianni, &
Brown, David L. "Aspirin for the Primary Prevention of Cardiovascular Events in
Women and Men." Journal of the American Medical Association vol 295, no. 3, 2006. p.