OBJECTIVES: Over 1.5 billion people worldwide suffer from hearing loss (HL). The great majority (83 %) goes untreated, which causes costs of over $ 980 billion per year. The aim of this study is to identify published estimates of costs of unaddressed HL for different country settings and subgroups. These cost estimates are a basis to model the cost-effectiveness of interventions to treat HL, such as bone-conduction devices or middle ear implants.

METHODS: Recent literature on costs of unaddressed HL was reviewed and healthcare costs, educational costs and productivity losses were extracted.

RESULTS: Most studies do not include all dimensions of costs; therefore, a comprehensive estimate of costs is not available for most countries. The per person excess healthcare costs of untreated HL are substantial and amount up to 6 % of GDP per capita. There is a considerable heterogeneity in the estimated costs of educational support for hearing impaired children (2 % to 134 % of GDP per capita) and in the economic costs of reduced productivity (up to 28 % of GDP per capita). In all but three studies, the association between the costs and degree of HL is not addressed, disregarding the fact that the severity of HL is an important predictor of health and societal costs. Cost estimates within the reviewed studies can be considered conservative as none of the studies includes unilateral HL. Most studies focus on high-income settings. Due to methodological differences, a comparison of costs between countries does not seem purposeful.

CONCLUSIONS: Longitudinal studies generating long-term evidence on comprehensive costs for uni- and bilateral HL by severity of hearing impairment in children and adults are needed, especially in low- and middle-income-countries. This gathered evidence should be used for cost-effectiveness analyses of interventions such as bone-conduction devices or middle ear implants.