Racial/Ethnic and Sex Representation in US-Based Clinical Trials of Hearing Loss Management in Adults: A Systematic Review

Importance: Although the National Institutes of Health (NIH) mandated the inclusion and reporting of women and racial or ethnic minority groups in NIH-funded research in 1993, little is known regarding the representation of women and racial or ethnic minority groups in trials that investigate hearing loss management. Objective: To assess sex and racial/ethnic representation in US-based clinical trials of hearing loss management in an adult population. Data Sources: Pertinent studies were identified using search strategies in PubMed, Embase, and ClinicalTrials.gov. Study Selection: Our search strategy yielded 6196 studies. We included prospective studies that were written in English, performed in the US, and evaluated hearing loss management in adults, including amplification devices, such as hearing aids or assistive listening devices, cochlear implants, aural rehabilitation, and therapeutics. Given its prevalence, only studies that addressed bilateral sensorineural hearing loss were included. Data Extraction and Synthesis: Data from 125 studies were extracted. The Preferred Reporting Items for Systematic Reviews and Meta-analyses diagram for systematic reviews was used for abstracting data. The guidelines were applied using independent extraction by multiple observers. Results: Among 125 clinical studies performed from January 1990 to July 2020 regarding hearing loss management, only 16 (12.8%) reported race/ethnicity, and 88 (70.4%) reported sex. Of the 16 studies that reported race/ethnicity, only 5 included more than 30% non-White representation. Among the 88 articles that reported sex, 44 (35.2%) reported more than 45% female representation. While the mean number of participants included in the observed trials was 80 (range, 7-644), the median number of participants from racial or ethnic minority groups in studies that reported race/ethnicity was 9 (range, 1-77), and a median of 12 female participants were included in studies with a numerical breakdown by sex. A mean of 41% (range, 1.55%-77.5%) of participants were female among studies that reported sex, and a mean of 30% (range, 1.96%-100%) of participants were from racial or ethnic minority groups among the 16 studies that reported race/ethnicity. Reporting of race/ethnicity varied substantially by funding source and journal type, while reporting by sex differed only by journal type. Conclusions and Relevance: Studies investigating hearing loss management do not adequately reflect the US population. A closer examination of the inclusion of diverse adults in clinical research associated with hearing health may work to ameliorate disparities and contribute to the development of tailored interventions that address the needs of an increasingly diverse US population.