Effects of providing free hearing aids on multiple health outcomes among middle-aged and older adults with hearing loss in rural China: a randomized controlled trial

Background Hearing loss has been associated with serious health problems around the globe. Previous studies have found the positive effects of fitting hearing aids on health, but few studies were conducted in developing countries. The aim of this study is to examine the effects of hearing aids on multiple health outcomes among middle-aged and older adults with hearing loss in rural China. Methods In this randomized controlled trial (RCT), participants aged 45 and above were randomly assigned to the treatment group prescribing with hearing aids or to the control group with no intervention. Trial outcomes for 385 participants were collected during the 20-month follow-up study. Using the difference-in-difference approach, our primary outcomes were hearing-related quality of life (QoL) and generic QoL. Results The intervention led to improvements in hearing-related QoL, presenting as the reduction in Hearing Handicap Inventory for the Elderly Screening Version (HHIE-S) scores (interaction coefficient = − 2.86, p = 0.005), HHIE-S-Emotional scores (interaction coefficient = − 1.42, p = 0.029), and HHIE-S-Situational scores (interaction coefficient = − 1.43, p = 0.007). The intervention was also effective in alleviating the increase in depressive symptoms (interaction coefficient = − 0.14, p = 0.042). Subgroup analysis revealed that the effects were only shown among people with social activities or active social networks. Conclusions Our study is the first RCT in China to measure the health effects and heterogeneity of hearing aid interventions. Wearing hearing aids can help improve hearing-related QoL and alleviate the increase in depressive symptoms. The intervention is expected to be applicable to similar settings in other developing countries to combat hearing-related health problems. Trial registration Chinese Clinical Trial Registry, ChiCTR1900024739 . Registered on 26 July 2019.