Leveraging publicly available data to evaluate health reform: establishing a methodology to assess the future impact of over-the-counter hearing aids

Health systems are complex and health reform is uncertain. With an aging global population, chronic health conditions are increasing and have become a priority for policymakers. Hearing loss is the third most common chronic condition among older adults and if left untreated, is associated with poor health and social outcomes. In the US, accessibility and affordability have been significant barriers to hearing aid utilization. Through new reform, over-the-counter (OTC) hearing aids are now available. This study demonstrates how publicly available health data was used to establish a methodology to define, characterize, and analyze the target population of this reform. In this retrospective cross-sectional cohort analysis, data from the National Health Interview Survey (NHIS) was utilized, with a sample that included respondents from the 2021 NHIS Sample Adult Interview. Three hearing aid groups (Active, Potential, General) were defined using questions from the NHIS annual core questionnaire and a baseline population health framework was developed. Binary logistic regression confirmed that the framework sufficiently described two group comparisons (Active-Potential, Active General) and also identified the key determinants of hearing aid utilization. Classification and regression tree (CART) classification amply predicted active hearing aid users and verified the key determinants as important predictors. These findings aligned nicely with literature published before OTC hearing aids were made available, confirming the NHIS to be consistent and representative. Our methodology can be repeated to examine the impact of OTC hearing aids in the post-implementation period and similar approaches should be taken to examine other emerging health reforms.