Absolute number of male, female, and unspecified subjects included in (A) all manuscripts, (B) by journal, (C) in US domestic and international studies. Distribution of included males, females, and unspecified subjects between journals and between domestic and international studies was different (p<0.0001). (D) Number of male subjects included by specialty. (E) Number of female subjects included by specialty. (F) Number of unspecified subjects included by specialty. Distribution of included males, females, and unspecified subjects was different by specialty (p<0.0001).