It is known that biomedical research studies include a disproportionate share of non-Hispanic White, middle-aged men. I am no expert, but it is obvious to me that research is most valuable when it reflects the diversity of our patient population and, indeed, our country. On this day that honors Jackie Robinson and his legacy in breaking baseball’s color line 75 years ago for my beloved Dodgers (then the Brooklyn Dodgers, now the Los Angeles Dodgers), it seems particularly timely to see an article published asking this question about sleep surgery research.
I had the good fortune of working with Megan Durr, MD when I was at the University of California, San Francisco, and I was so happy to see a recent article from her team examining the racial and sex distribution of published studies in adult sleep surgery. From 148 studies published between 2016 and 2020 that comprised 13,078 participants, 84% were male (the figure was 83% for US-based studies). Surprisingly, only 4 US-based studies presented race/ethnicity data (and just 13 overall), with 83% of participants being White. The publication presents a thoughtful, appropriately-forceful discussion of the need to do better, highlighting some of the historical and other barriers to addressing this inequity.
Numerous population-based studies have shown differential rates (prevalence) of obstructive sleep apnea around the world, with especially high rates in Asia. At least some of the variation in the prevalence of sleep apnea around the world is likely due to factors that we think are important in sleep apnea such as jaw structure (craniofacial), obesity, and fat distribution that may be associated with race/ethnicity and/or sex. It is unclear whether current descriptions of race and ethnicity used by many groups like the National Institutes of Health are meaningful (in today’s world it is common for individuals to be multi-racial) or accurately reflect the factors that are most important to the feature of interest (I am considered a non-Hispanic White but have a jaw structure that is similar to a stereotypical Asian pattern). However, collecting and reporting race/ethnicity and sex information – along with the factors like jaw structure and neck circumference that we think may explain the associations between OSA and race/ethnicity and gender – is the first step to understanding how important these are not only to the prevalence of sleep apnea but also to treatment outcomes.
The prevalence of obstructive sleep apnea higher among Black, Hispanic, and Asian individuals, and those groups are massively underrepresented in sleep surgery research studies. Here is my take on some of the factors that must be addressed to make sleep surgery research more representative:
- Diagnosis of sleep apnea. Enrollment in sleep surgery research studies starts with establishing a diagnosis of obstructive sleep apnea. It is estimated that 80-90% of individuals with obstructive sleep apnea are not diagnosed. While some of them (for example, those with mild obstructive sleep apnea but no obvious issues) may not need treatment, clearly many individuals have significant obstructive sleep apnea but have not been diagnosed. Unfortunately, healthcare disparities start with access to care, and in the US we have not addressed critical issues of equitable access to sleep-related health care. Beyond this, women with obstructive sleep apnea are known to present with different signs and symptoms, such that – even though men have a higher risk of developing sleep apnea – women are classically underdiagnosed.
- Follow up care for those who do not do well with positive airway pressure therapy. Surgery is not a first-line treatment for the typical adult with obstructive sleep apnea, so generally adults will have a trial of positive airway pressure before considering surgery. Many patients who do not do well with positive airway pressure are lost to follow up, and limitations in access to sleep medicine care make this even more likely.
- Sleep surgery care. There are relatively few surgeons who have a dedicated interest in sleep surgery, and I would argue that my colleagues and I are more likely to work in hospitals that see a greater proportion of non-Hispanic white patients than in the general population. This does not help the over-representation. As we train more sleep surgeons, we hope the distrubution of sleep surgeons across all hospitals.
- Enrollment in sleep surgery studies. The history of medical research around the world, including in the United States, has examples of appalling abuses of authority and violations of ethical standards. These have disproportionately affect non-White populations, leading to an understandable reluctance to participate in medical research and, indeed, wariness of the medical establishment. There is no easy way to address this other than to conduct research with strict adherence to ethical principles and approved policies for human subjects research.
Because groups with poorer access to care end up being less likely to be enrolled in studies, these groups may then be less likely to be helped by research. In effect, this may widen disparities in health outcomes. I often think about what we can do to change this. I am sure there is no easy, quick solution, but it is encouraging that the National Institutes of Health is requiring an even sex distribution for some research studies, especially smaller studies where this should be very doable. One can only hope that efforts like these and greater awareness of and attention to this problem improve it. I actually hope that attention may be focused similarly on age, which is associated with the prevalence of obstructive sleep apnea and which I think is associated with outcomes of surgery.
There may be important racial/ethnic differences not only in the causes of obstructive sleep apnea but also in the outcomes of treatment, and we need to learn more!