The use of the Washington Group on Disability Statistics questionnaires to identify hearing disability: a systematic review.

Purpose: To investigate the use of instruments from the Washington Group on Disability Statistics (WG) to obtain data on hearing disability (HD).
Research Strategies: We conducted searches in the PubMed, Scopus, Science Direct, Web of Science, Lilacs databases and the grey literature. The software "The State of the Art through Systematic Review" and "Mendeley" were used to assist in the bibliographic reference organization, selection, and storage.
Selection Criteria: we followed the guidelines proposed by the "Preferred Reporting Items for Systematic Reviews and Meta-Analysis" and we selected studies that met the following inclusion criteria: written in English or Portuguese, within the period of 2001 to 2017 and have used the WG hearing disability question.
Data Analysis: The variables analyzed into the studies were: WG module, country and year of data collection, sample size and composition, objective of the study, publication journal, HD estimate of prevalence and accuracy measures.
Results: Sixty-five studies are included in the review, conducted with data from 30 countries. The WG Short Set of question was the most often used. Hearing disability prevalence ranged from 0.2 to 2.3% and only three studies estimated the accuracy of the instrument to identify HD.
Conclusion: The hearing disability question of WG has been used worldwide and mainly in developing countries. The short variation in the estimated prevalence measurements within studies seems favorable to the WG's goal of generate estimates that allow international comparison. However, the shortage of validity studies indicates the need for further investigations with this purpose.