Background: Globally, it is estimated that approximately 1.3 billion people live with some form of hearing impairment. Major causes of hearing loss include infection/disease, age-related factors, and occupational factors. Numerous systematic reviews and meta-analyses have attempted to synthesise literature on these topics. To date there has not been a systematic evaluation of the relationships between hearing impairment and diverse physical, mental, and social outcomes.Objective: We performed an umbrella review of systematic reviews of observational studies with meta analyses for any physical disease, biomarkers of disease, mental health or cognitive outcomes, and/or modifiable risk factors associated with hearing impairment.
Methods:For each meta-analytic association, random-effects summary effect size, 95% confidence intervals, heterogeneity, evidence for small-study effect, excess significance bias and 95% prediction intervals were calculated, and risk of bias was assessed via the AMSTAR2 tool. These were used to grade significant evidence (p<0.05) from I to IV, using the recommendations from the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) criteria.Results: From 3,747 studies, 21 were included covering 54 outcomes. Overall, 44/54 outcomes (82%) yielded significant results. Of the highest quality evidence, age related hearing loss and non-specific hearing impairment was negatively associated with several types of cognitive impairments; paediatric bilateral hearing loss was negatively associated with quality of life; sensorineural hearing loss was