Documenting Sex and Sex Differences in Animal Studies

The National Institutes of Health reports that women now represent nearly half of all participants in clinical research (https://grants.nih.gov/grants/guide/notice-files/NOT-OD-15-102.html). At Thrombosis and Haemostasis, we have indeed published several clinical articles, specifically highlighting the effects of gender differences in recent years.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] In contrast, basic and preclinical studies are more often and at times traditionally conducted in male animals. This can lead to an underappreciation of sex differences and their influence in health and disease, despite sex being not only an important experimental variable but also a notable factor determining cardiovascular outcomes, for example, stroke risk in atrial fibrillation, as well as platelet function and antiplatelet therapy in women.[3] [4] [6] [11] [12] [13] [14] Hence, we would like to follow the good example implemented by the Arteriosclerosis, Thrombosis, and Vascular Biology Council[15] [16] and commit ourselves to regularly monitoring sex and sex differences in animal studies published in Thrombosis and Haemostasis. This report should help elaborating an editorial approach regarding the requirements for documenting sex when conducting animal studies to be submitted to our journal.