Income Level, Literacy, and Access to Healthcare Rarely Reported in Clinical Trials

Study Suggests Data Gaps Might Create Healthcare Blind Spots

Clinical trials published in high-profile medical journals rarely report on income or other key sociodemographic characteristics of study participants, according to a new study that suggests these gaps may create blind spots when it comes to healthcare, especially for disadvantaged populations.

The study, published this month in JAMA Network Open, analyzed 10% of 2,351 randomized clinical trials published in New England Journal of Medicine, JAMA, The BMJ, The Lancet, and Annals of Internal Medicine between January 1, 2014 and July 31, 2020.

The most commonly reported sociodemographic variables were sex and gender (in 98.7% of trials) and race/ethnicity (in 48.5%). All other sociodemographic data (such as income, literacy or education level, language preference, or housing status) were reported in less than 15% of the trials.

“Randomized trials can only work for everyone if they include everyone,” said Dr. Aaron Orkin, a researcher and emergency physician at St. Joseph’s Health Centre of Unity Health Toronto who led the study. “The results of randomized trials affect everybody because they determine how we promote health and how we diagnose and treat disease. If trials don’t report on the characteristics of the people being studied, there is no way to know that the study’s findings will apply to all populations.”

The research found that education level or literacy was reported in 14.3% of studies examined, 5.9% reported income or socioeconomic status, and 4.6% included details about participants based on a social determinant of health, such as health insurance or employment status.

“People who face discrimination or disadvantages should have confidence that research being done to benefit them is inclusive,” said Dr. Nav Persaud, a scientist at the MAP Centre for Urban Health Solutions of St. Michael’s Hospital of Unity Health Toronto and coauthor on the paper.

The authors argue that experiences and outcomes of a disease across cultures, races, income levels, living situations, genders, and other variables will be different. Studying a disease and its treatment in limited groups ultimately limits the applicability of the research. The authors hope to use the initial information reported in this study to focus on reporting of social determinants in trials in specific disease areas and to change standards in conducting research.

 Edited by Gary Cramer