The World Health Organization’s hearing-impairment grading system: an evaluation for unaided communication in age-related hearing loss

Abstract

Objective: This review evaluated the data from five datasets having pure-tone thresholds and functional measures of speech communication from relatively large groups of older adults to evaluate the validity of the proposed new World Health Organisation (WHO) hearing-impairment grading system, referred to here as WHO-proposed.

Design: This was a review of studies identified from the literature having both pure-tone audiometry and functional measures of speech communication from relatively large samples of older adults.

Study sample: Three population or population-sample datasets and two clinical datasets were identified with access provided to de-identified data for five of these six studies.

Results: As the WHO-proposed hearing-impairment grade progressed from “normal” to “severe” (insufficient data from older adults were available for the “profound” category), each step in this progression led to a significant difference in functional communication relative to the preceding step. Cohen’s d effect sizes were moderate to very large between each successive step on the WHO-proposed hearing-impairment grading scale, with some exceptions for the step from “normal” to “mild/slight” grades.

Conclusions: The WHO-proposed hearing-impairment grading system, recently developed through expert opinion and adopted by WHO, is validated here with evidence from studies of functional communication in older adults.

Keywords:

• Aging
• hearing loss
• World Health Organisation (WHO)
• severity
• communication

Acknowledgements

This review would not have been possible without the assistance of several individuals who either provided access to the de-identified data for this evaluation (B. Gopinath for the Blue Mountains Hearing Study, Richard Wilson for the Wilson 2011 VA dataset, Victoria Williams-Sanchez and Gary Kidd for the Williams-Sanchez et al. 2014 VA dataset) or performed the analyses requested (Karen Cruickshanks and Alex Pinto for the Epidemiology of Hearing Loss Study 2 dataset). Alex Pinto’s effort on these analyses was supported, in part, by a research grant from the National Institute on Aging, R37AG011099. The content is solely the responsibility of the author and does not necessarily represent the official views of the National Institutes on Health.

Disclosure statement

No potential conflict of interest was reported by the author.