The Growing—and Now Alarming—Burden of Hearing Loss Worldwide
Additional findings that surprised us are that 1.34 billion people now have mild-to-complete hearing loss (20 dB or worse), comprising 18.1% of the world's population; hearing loss is now the fourth leading cause of years lived with disability (YLDs) worldwide; and the YLDs due to hearing loss are 5.8% of the sum of YLDs due to all causes. These are staggering figures, especially the last one.
The data from the GBD studies were analyzed by us to 1) calculate prevalences without the adjustments used in the GBD 2015 to reduce prevalences according to estimated uses of hearing aids and 2) enable direct comparisons of YLDs for all hearing loss across the studies (the methods are presented in the online appendix to the Lancet paper). The first set of calculations recognizes the fact that use of hearing aids is exceedingly low in most world regions (4–8) and allows comparisons with results from all other world surveys to date, which don’t include the adjustments for estimated uses of hearing aids. The second set of calculations allows “apples-to-apples” comparisons as opposed to comparing a subset of hearing loss presented in the results for the 2010 and 2013 GBD studies (mainly age-related hearing loss) and a superset presented in the results for the GBD 2015 (for all sense organ diseases). The direct comparisons indicate that the rankings of YLDs for all hearing loss increased from number 11 in 2010 to number 4 in 2013 and 2015.
The change in rankings was largely attributable to updates in the disability weights first used for the GBD 2103 (9). As noted in the Review, the updates reflected an increasing appreciation of the importance of hearing loss for gauging overall health and wellbeing.
These various findings show that, despite the current and previous efforts by the WHO, national governments, non-governmental organizations, and individual hearing health care (HHC) professionals, the burden of hearing loss has grown markedly over the years and there are no signs that the growth is slowing. And those efforts have been conducted by supremely capable and dedicated people and organizations. But the burden continues to grow.
Clearly, something more is needed in both personnel and funding first to halt the growth in the burden and then to reduce it from that point forward.