Lack of sex-specific clinical research threatening quality radiology care

Gender is a poorly controlled—and often neglected—variable in radiology human subjects research, a group of Atlanta scientists report in the current edition of the Journal of the American College of Radiology. The resulting lack of sex-specific research could have a profound impact on quality of care.

“Despite abundant data to the contrary, women have often historically been considered suboptimal research subjects given inherent hormonal and reproductive differences from men and perceived challenges in recruiting,” corresponding author and lead researcher Patricia Balthazar, MD, and colleagues in the department of radiology and imaging sciences at Emory University said. “[They] have traditionally been underrepresented in clinical trials, thus contributing to a paucity of meaningful data for women and their healthcare providers regarding gender-specific risks and benefits of certain treatments and diagnostic procedures.”

The rocky road is a result of decades of indecision on the matter, Balthazar et al. wrote in JACR. In 1977, the FDA banned women from participating in clinical trials altogether, citing concerns about fetal safety, while nearly two decades later the National Institutes of Health mandated female inclusion in such studies. Further reporting eventually led to a 2014 NIH initiative to equalize gender within cell and animal research.

Controlling for gender in these trials is key, the authors said, since myriad medical conditions present differently in women than in men. Different sexes can have unique responses to the same medical conditions, and documenting those can facilitate individualized treatment in a patient-centered era.

“Nonetheless, several recent studies in medical fields other than radiology have shown that gender bias persists in both basic and clinical research and that gender remains a poorly controlled variable in many trials,” Balthazar and co-authors said.

Balthazar and her team at Emory conducted a bibliometric analysis of 522 research articles published in seven of the most commonly cited general radiology journals during a six-month period in 2016. The researchers manually extracted the number and gender of participants for each article, noting whether gender-based results were reported in each case.

Of the hundreds of articles that met their search criteria, a minority—less than 10 percent—ignored gender altogether. Ninety percent did account for male or female sex, with 147 articles favoring female subjects and 308 favoring males. Still, the authors said, aggregate data found 41.6 percent of all subjects in the studies were male and 55.9 percent were female.

“In nearly one in 10 articles, there was no mention at all of the gender distribution of research subjects,” Balthazar et al. wrote. “And in those that indicated including subjects of both genders, only about one in four reported any gender-based results.”

The journals Radiology, European Radiology and the American Journal of Roentgenology were the three publications that most often specified the gender of subjects in studies, the authors said. The Journal of the American College of Radiology fell last on the list of seven.

“Our findings comport with those of authors outside of radiology suggesting that researchers often exhibit gender bias and/or gender neglect in their published works,” Balthazar and colleagues said. “Because clinical research serves as the basis of evidence-based medicine and the further advancement of scientific discovery, initiatives to improve the reporting of gender-specific results may help catalyze otherwise overlooked discoveries.”