RP209 - Measurement Matters: Audiologist Role in Measuring Hearing in Epidemiological Studies

Hearing loss is common among older adults. Following recent epidemiologic research linking hearing loss to risk of negative outcomes, including falls, dementia, depression, and physical function, it has been thrust into the public health arena. However, the majority of evidence comes from a limited number of studies mostly from the United States and Europe as hearing is rarely measured in epidemiologic studies. Recent advances in portable audiometry have made inclusion of hearing measures feasible. This presentation covers experiences and data from two efforts incorporating hearing measures into large epidemiologic studies.  

The National Health and Aging Trends Study (NHATS) is a nationally-representative study of Medicare beneficiaries 65 years and older and added hearing measures in Round 11. The NHATS conducts field research in participant homes across 48 continental United States using over 250 technicians and oversamples underrepresented populations, i.e., Black older adults and adults 90 years and older.   

The Longitudinal Aging Study in India (LASI)-Diagnostic Assessment of Dementia is a sub-sample from the main LASI study of 4000 participants 60 years and older. LASI-DAD is a first-in-kind study center-based in urban and rural areas in India, with 100 technicians in 18 states performing assessments and unique oversampling for those at high risk of cognitive impairment. Despite initial doubts about feasibility in noisy urban centers of India, hearing measures were added in wave two of LASI DAD.

Quality assurance and control designs for adding hearing measures were customized for both studies. Picture-based manuals, training videos, and related materials for NHATS and LASI-DAD were developed by audiologists and epidemiologists. Interviewers, who typically know little about hearing, for both studies were trained by audiologists over fundamental aspects of hearing, importance of measuring hearing, and how to complete hearing testing. Examination of between-ear and -frequency differences in thresholds, time, and false positives identified potential concerns in the data. Headphone calibration was completed yearly with field-based biologic checks conducted by staff and equipment was randomly audited for quality by the audiologist responsible for the study.  

NHATS Round 11 has hearing data on 73% of all participants. Participants without testing in this study were those who chose not to have it, or testing time was shortened due to heavy covid precautions. Hearing loss affects about 65.3% of adults 70 and older and 91% of adults 85 and older in the United States. LASI-DAD Wave 2 has hearing data for 86.5% of study participants thus far. Hearing testing is not completed on participants with turbans unless they remove them. In LASI-DAD, hearing assessment length declined from ~11 to ~5 minutes over the first 6 months of training and data collection. Following 1654 assessments, 40% were flagged for review by qualified audiologists and only 19 were rejected as invalid results. Prevalence estimates of Indians with hearing loss are 74.3% of adults aged 71 years and older and 86.7% of those older than 85 years. 

These data show feasibility of adding hearing measures in epidemiologic studies. Moreover, hearing loss prevalence nationally and globally informs researchers, clinicians, and policy makers to take appropriate measures for mitigating the risk of negative outcomes.