Sociodemographic Disparities Persist in Ophthalmological Clinical Trials

An analysis of more than 600 ophthalmological clinical trials suggests the inclusion of diverse and representative data sets remains limited, despite efforts to improve generalizability.¹

The research validates prior ophthalmological clinical trial reviews suggesting trials consist mostly of White participants from high-income countries, with an underrepresentation of racial and ethnic minorities.

“Overcoming the burden of eye disease on marginalized populations is contingent on their inclusion in clinical ophthalmological trials,” wrote the investigative team. “Given how trials inform further research and funding (and ultimately treatment availability), the systematic underrepresentation of already marginalized communities has only served to widen the eye health chasm, one which is currently largely attributed to poor access to care.”

The team, led by Luis Filipe Nakayama, Laboratory for Computational Physiology, Massachusetts Institute of Technology, identified clinical trials as guides for the treatment of various ophthalmic diseases with distinct presentations, pathological characteristics, and responses to treatment in minority populations. Currently, both the National Institute of Health (NIH) and the US Food and Drug Administration recommend reporting gender and race and ethnicity to promote generalizability and representation.

As minority subgroups are often underrepresented in ophthalmological clinical trials, which limits generalizability, the impact of socioeconomic inequality could become more pronounced. The investigators’ review aimed to analyze sociodemographic disparities in ophthalmological phase 3 and 4 trials based on publicly available data from clinicaltrials.org.

The review extracted data on country distribution, race, ethnicity, gender, and funding characteristics. Investigators included clinical trials with an ophthalmology theme, any language, and without date restriction, whilst excluding non-ophthalmological studies, ongoing trials, non-available results, and studies in phases 1 and 2.

Investigators identified a total of 21,413 trials with their initial search and excluded 20,239 trials for not meeting inclusion criteria. After analysis, another 520 non-ophthalmological and duplicated articles were excluded, leaving 654 clinical trials included in the final review from 1990 to 2022.

Within the clinical trials, 93,421 patients were male (47.0%) and a total of 69 countries were represented. Investigators identified the top 11 of the 69 countries were classified as high-income countries. In 84% of the included clinical trials, the study population came from high-income countries.

Moreover, data showed race was described in 37% of the clinical trials. The incidence of race and ethnicity reporting was shown to improve during the last 7 years of study. The findings suggest the number of studies that did not describe race was higher in 2012 and decreased over time, with 76% of completed clinical trials in 2021 through July 2022 including race description.

However, a description of race was less frequent in the four most studied ophthalmological specialty areas (cornea, retina, glaucoma, and cataracts). Among included studies with at least 1 US location, race was described in 53% of studies, and in studies outside the US, race was described in 20% of studies.

Investigator noted the lack of incentive to perform clinical trials or research in research-limited countries. As this perpetuates the global knowledge gap and drives a divide between rich and poor countries, they stress the need for advocacy surrounding medical research.

“Advocacy from within the research community, governments and non-government players such as the World Health Organization (WHO), is necessary to increase representativeness and improve the applicability of medical research to those who are most burdened by disease,” investigators wrote.

References

1. Nakayama LF, Mitchell WG, Shapiro S, et alSociodemographic disparities in ophthalmological clinical trials. BMJ Open Ophthalmology 2023;8:e001175. doi:10.1136/bmjophth-2022-001175