Gender Disparities in First Authorship at Three Medical Universities in an Area Affected by the Great East Japan Earthquake

The Great East Japan Earthquake that occurred on March 11, 2011, was one of the largest natural disasters in modern times. Publication in medical journals is important aspects of the academic promotion process, and is thus important for all scientists. However, little is known about whether and how substantial natural disasters affect gender disparities in academic productivity in disaster-affected areas. We hypothesized that the Great East Japan Earthquake widened the existing disparities in scientific publishing between male and female researchers. To test this hypothesis, this retrospective observational study using existing databases was conducted. We extracted from the MEDLINE database all types of biomedical articles published from March 11, 2007, to March 11, 2015, by three medical universities in a disaster-affected area of Japan. Differences in the proportion of female first authorship during the 4 years before and after the Great East Japan Earthquake were compared. A total of 5,873 papers were analyzed. The proportion of female first authors significantly declined after the Great East Japan Earthquake (20.5% vs. 14.1%; odds ratio 0.64; 95% confidence interval 0.56-0.73). A similar trend was identified across all prespecified subgroups, including clinical department; original article; public medical university; and prestigious journal with impact factor >6. Reference data from two medical universities minimally affected by the Great East Japan Earthquake showed the opposite trend. These results collectively suggest that large natural disasters can reinforce existing gender disparities in first authorship in biomedicine.