CDME Module 2: Vision, Hearing, Diabetes Mellitus-Hearing and Vestibular Function and Commercial Vehicle Driver Safety Evidence Report

Hearing and Vestibular Function and Commercial Vehicle Driver Safety Evidence Report

Pdf Summary

This document is an executive summary of a report on hearing, vestibular function, and commercial motor vehicle driver safety. The purpose of the report is to provide information to the Federal Motor Carrier Safety Administration (FMCSA) in order to update their medical standards and fitness-to-drive examination guidelines. The summary covers five key questions: the relationship between hearing impairment and motor vehicle crashes, the validity of the forced-whisper test for measuring hearing ability, the impact of vestibular dysfunction on crash risk, the length of time after a vertigo episode until it is safe to drive, and the effectiveness of treatments for Ménière's disease.<br /><br />For key question 1, there were no studies found that examined the relationship between hearing loss and crash risk specifically among commercial motor vehicle drivers. However, evidence from studies on private driver license holders suggests that individuals with hearing impairment are not at an increased risk for a crash.<br /><br />Regarding key question 2, the forced-whisper test is considered a viable tool for screening for hearing loss, but it has limitations that make it less useful as a diagnostic tool. While it has high sensitivity for detecting hearing impairment, it also has low specificity and may label individuals with normal hearing as hearing impaired.<br /><br />Key question 3 found no studies that examined the relationship between vestibular dysfunction and crash risk among CMV drivers. Therefore, no evidence-based conclusion can be drawn at this time.<br /><br />Key question 4 did not find any studies on the length of time needed after a vertigo episode for an individual to be considered safe to drive.<br /><br />For key question 5, the report found that diuretics do not appear to be effective in treating vertigo and hearing loss in individuals with Ménière's disease. Betahistine may be effective in reducing vertigo but not hearing loss. No conclusion could be drawn for the effectiveness of diphenidol or intratympanic gentamicin. The impact of endolymphatic sac shunt surgery on vertigo and hearing loss in individuals with Ménière's disease could not be concluded at this time.<br /><br />Overall, the evidence base for most of the key questions was limited, and no significant conclusions could be drawn based on the current available evidence. Further research is recommended to provide more information on these topics.

Keywords

hearing impairment

motor vehicle crashes

forced-whisper test

vestibular dysfunction

crash risk

vertigo episode

Ménière's disease

diuretics

betahistine

endolymphatic sac shunt surgery