Gender disparities among prestigious biomedical award recipients in Japan: A cross sectional study

The limited inclusion of women in medical and biomedical research has been a long-standing global issue.¹ Gender and racial inequity continue to pervade contemporary society, including domains such as in leadership positions,^2-5 remunerations,⁶ research publication citations,⁷ and professional awards.^{8, 9}

The gender gap has been observed in the number of original papers,^{7, 10} which is an important indicator for evaluating performance, and the proportion of women first author is lower in women scientists.¹⁰ Moreover, opportunities for women scientists to present and gain recognition at academic conferences have been limited,¹¹ and a similar gender gap has also been reported in the chance of obtaining grants.^{12, 13} Accumulating these gaps may result in a lower proportion of women in the professional awards.

Previous research investigating the proportion of women among prestigious awards, such as the Nobel Prize,¹⁴ the Lasker Award,¹⁵ and other diverse international research awards,¹⁶ has illuminated the underrepresentation of women within scientific research fields; only 2.7% of Nobel Prize recipients and 7.8% of Lasker Award winners were women. One of the documented reasons for the observed disparities among Nobel Prize winners before 1967 is the lower proportions of women than men among nominees.¹⁴ However, women's underrepresentation in prestigious awards is presumably caused by a combination of multiple causes including gender discrimination and gender bias.

Historically in Japan, the Basic Law for a Gender-Equal Society enacted in 1999 has provided milestones and general guidelines for promoting gender equity in society, including academia. Nevertheless, gender gaps still pervade in Japanese higher education,¹⁷ with women representation in undergraduate 45.6%, in master courses 31.7%, and doctoral courses 34.2%, respectively in 2022.¹⁸ Remarkably in academia, Japan stood out with strikingly few female academic authors compared with other high-income countries.⁹ The number of academic papers is one of the important indicators for evaluating scientific performance.¹⁰ Thus, it is reasonable to hypothesize that there might also be a gender gap in the award conferral stage in Japan. However, few studies have assessed the circumstances surrounding women representation in Japan.

To improve such gender imbalance, Japanese government and universities have begun to promote women's empowerment with relevant policies or practices, emphasizing the importance of diversity, equity, and inclusion, and women in science. For instance, under the 6th Science, Technology, and Innovation Basic Plan, Japan set their milestone to achieve the proportion of women in university up to 23% until 2025.¹⁹ The Tokyo Institute of Technology is initiating affirmative action for undergraduates, and approximately 14% of student places at the institute are now exclusively available to female applicants.²⁰ More recently, the University of Tokyo disclosed its 5-year scheme to hire 300 women professors and associate professors, aiming to boost the number of female scientists.

Scrutinizing women representation of award recipients in Japan and analyzing if potential inequities have improved after such political/grass-root practices should be of interest, and this might help unveil specific circumstances that potentially cause a gender gap in Japan. Herein, we investigate the proportion of women among prestigious medical and biomedical award recipients in Japan.

In this cross-sectional study, we scrutinized three notable Japanese awards in the field of medical and biomedical sciences, each with prestige that warrants speculation regarding potential future Nobel laureates. These awards under scrutiny included the Takeda Prize for Medical Science (established in 1954), the Uehara Prize (established in 1985), and the Keio Medical Science Prize (established in 1996). One reason for choosing these awards is the public availability of the identities of their recipients. The Takeda Prize for Medical Science was chosen because this is one of Japan's most traditional honors with long history. The Keio Medical Science Prize was chosen because the honor represents a contemporary addition, with annual selections comprising one domestic and one international nominee, which made us compare the gender balance between international recipients and domestic recipients. The Uehara Prize was chosen because it was chronologically established in an intermediate of the other two. We excluded notable Japanese awards nominated from diverse fields of humanities, social, and natural sciences to distinguish the potential bias in the medical or biomedical field.

The primary criteria delineated by each foundation are as follows: the Takeda Prize for Medical Science is awarded to researchers with outstanding achievements in basic or clinical fields of medicine; the Uehara Prize is awarded to researchers with outstanding achievements in the life sciences, especially in fields related to health promotion, disease prevention, and treatment; the Keio Medical Science Prize is awarded to researchers with outstanding achievements in medicine and various fields of life science closely related to medicine. The selection processes of recipients for each award were scrutinized from their corresponding websites.

Recipients were identified from the official websites of each respective foundation. Subsequently, four authors independently classified each recipient based on their perceived gender (woman, man, or other), following established methods.^{1, 15} Gender categorization is reported in binary (woman or man) in this study, as there were no cases found during our search where recipients' pronounce were as “they” or “hir,” nor did any recipients fall into alternative categories. When categorization was not consistent between authors for some awardees, such discrepancies were resolved through comprehensive discussion between all authors. In addition, we scrutinized the interval between the awardee's terminal degree and award receipt, which we have defined as the “academic age.” The awardee's degrees were investigated through the National Diet Library database.²¹ Statistical analyses were performed with Microsoft Excel^®□.

Two hundred and thirty-three awards (139 Takeda Prizes for Medical Science, 68 Uehara Prizes, and 26 Keio Medical Science Prizes) have been conferred upon Japanese researchers (Table 1). Among these, 12 recipients won all three awards, while 39 received two, signifying those 182 distinct researchers received at least one (Figure 1). The timeframe between the awardee's terminal degree and award conferral was available for all researchers. The median academic age was 30 years for the Takeda Prize for Medical Science, 26 years for the Uehara Prize, and 28.5 years for the Keio Medical Science Prize awarded to Japanese researchers. Meanwhile, the Keio Medical Science Prizes presented 27 awards to international researchers, with a median academic age of 32 years.

Among Japanese recipients, strikingly, 100% of the Uehara Prize (68/68) and Keio Medical Science Prize recipients (26/26) were men, as were 98.6% (137/139) of the Takeda Prize for Medical Science recipients (Table 1). Among all three awards, only two recipients were women, receiving the Takeda Prize for Medical Science in 2015 and 2023: Kayo Inaba and Yukiko Goto (Table 1). These results substantiate the fact that women award recipients only appeared in the last decade in Japan. Both recipients earned a PhD in science, had a few years of research experience in the United States, and were promoted to professor at the same university where they earned their degrees. Their academic age at the award conferral was 37 years for Kayo Inaba and 31 years for Yukiko Goto, respectively.

On the contrary, 88.9% (24/27) of the Keio Medical Science Prize for international researchers were men and 11.1% (3/27) were women, the three were given in 1999, 2020, and 2021.

The average median academic age between the awardee's terminal degree and award conferral was 28.2 years. Over the last decade (2014 to 2023), 3.8% (2/53) of women comprised the three-award recipients, which is less than the proportion receiving doctoral degrees 28 years ago in 1995 (15.6%) in Japan.²²

Our investigation had limitations. First, the anonymity of the nomination process for each award precluded us from rating whether women were equally nominated at panels. Second is the potential misclassification of gender by researchers. On the other hand, the authors also note that gender perceptions of the recipients by third parties are important, as it is susceptible to bias.²⁹ Additionally, our methods were reported previously.^{1, 15} Third, the extreme gender gap we observed in the medical/biomedical field is not necessarily generalizable to the other scientific fields. The gap has been academically reported to vary among fields.^{28, 30, 31} Therefore, careful interpretation is required for our study. Lastly, our investigation did not reveal the causation of the gender gap at the award conferral stage. Clarifying at which stage is there the gender gap problem should be indispensable to address the issue.

Hayase Hakariya: Conceptualization; investigation; formal analysis; writing—original draft; writing—review and editing; supervision; data curation; methodology; visualization; resources; validation. Tatsuki Ikejiri: Investigation; writing—review and editing; data curation. Arisa Hakariya: Investigation; writing—review and editing; data curation. Mayumi Hara: Investigation; writing—review and editing; data curation.

The authors declare no conflict of interest.

All information was publicly available and ethics approval was not required. Data were collected from June 21 to August 17, 2023, and updated on December 15, 2023. This cross-sectional study was performed only with publicly available data, and no patients or individual patient record were involved. Therefore, no institutional review board approval and patient's informed consent were necessary.

The lead author Hayase Hakariya affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.