By Clinical Research News Staff

May 26, 2020 | After analyzing the trends in the types of 485,409 people enrolled in 60 studies from 1990 to 2018, Johns Hopkins Medicine researchers report that, although some progress has been made, women and older adults are still vastly underrepresented in lipid lowering therapy trials compared with their disease burden. 

The findings, recently published in the journal JAMA Network Open (DOI: 10.1001/jamanetworkopen.2020.5202), suggest that trials still aren’t reflecting real-world patient populations.

“Women and older patients carry significant burden of atherosclerotic cardiovascular disease,” the study’s authors write in a summation of their findings. “However, concerns exist that despite the high prevalence of cardiovascular morbidity among these subgroups, they are underrepresented in clinical trials.”

The authors acknowledge attempts made to improve the representation of affected populations. For instance, in 1986, the National Institutes of Health (NIH) advisory committee recommended inclusion of women to grant applicants. The US Food and Drug Administration (FDA) has also evolved over the years, making recommendations regarding reporting of sex and other demographic variables in randomized clinical trials (RCTs), which, the authors note, are considered the criterion standard for evidence-based medicine. In recent years, there has been an ongoing effort in industry-funded trials to recruit women and older patients.

“We want to ensure that the types of patients who will be using these drugs are the ones included in the clinical trials, so that we can determine if these medications are safe and effective for the people who are prescribed them,” Erin Michos, associate professor of medicine at the Johns Hopkins University School of Medicine and senior author of the study, said in an official statement. “Although we did see an improvement over the years in representation of women and older adults, that progress was rather modest. Clearly more still needs to be done to shift the balance to represent our patient demographics.”

For their study, the researchers reported an increase in the number of women participants from about 20% in the early 1990s to about 33% in the most recent trials analyzed. However, many trials included only women who were past menopause or who were unable to have children, particularly excluding people who were pregnant or breastfeeding. Only slightly more than half of the 60 trials reported results based on effectiveness by gender.

In the report on these studies, the percentage of trial participants 65 or older increased from 32% from the early 1990s, compared with 42% in the most recent trials examined. As with gender, only slightly more than half of the 60 studies reported their findings specifically for older adults.

“Clinical trials are designed to ascertain the efficacy and/or safety of a drug or device in a target population, and under-enrollment limits the evidence-base for these key demographic groups,” Michos and her colleagues stress. “... [P]ractical steps should be undertaken to develop new strategies to achieve optimal recruitment of these subsets of the population in RCTs, and investigators should be encouraged to report results based on these subgroups to enhance generalizability of their results.”