Dec 2020 The Hearing Journal
Antimicrobial therapies for certain diseases are known to cause ototoxicity or ear damage. In particular, patients with cystic fibrosis (CF) often undergo repeated antimicrobial therapy, increasing their chance of ototoxic side effects. For these patients, extended high-frequency audiometry is valuable in the early detection of hearing damage. However, diagnostic audiometry conducted by a trained audiologist in a sound booth is costly and time-consuming. Looking into a potential alternative to traditional hearing loss screening, a recent study found that self-administered tablet-based audiometry could be a practical and accurate screening tool for early detection of hearing loss among CF patients. “Individuals with CF have been shown to have a high prevalence of hearing loss due to ototoxicity from aminoglycoside antibiotics, but most centres do not have a screening program in place,” said study co-author Anand Shah, MD, PhD. “In large part, this relates to the barriers in obtaining regular sound-booth audiometry, with audiology centres often not co-located with CF units alongside the requirement for further outpatient appointments and specialist staff.”
The study stressed that “sound-booth audiometry is costly, time- and labor-intensive, and impractical in large cohorts on a frequent basis.” This, according to the authors, was “particularly pertinent within resource-poor countries, where ototoxic effects are even more prevalent.”
In recent years, there has been increased attention to how web-based or mobile ototoxicity monitoring programs (OMPs) could help streamline clinical care. However, studies that validated this technology have focused on healthy individuals with hearing loss. Until now, there has been no research into how smartphone or tablet hearing tests could work for adults with chronic lung disease. “In our study, we aimed to analyse the burden of hearing loss in an adult CF cohort but importantly also assess novel tablet and web-based audiometry as screening tools with regards to accuracy and usability,” said Shah.
Two key results from the study pointed to the accuracy and usability of tablet audiometry. Using the app SHOEBOX Audiometry together with RadioEar DD450 circumaural headphones, participants took the tablet-based test assisted by non-audiologist researchers. The tablet audiometry “showed high negative predictive value in screening for hearing loss with additional good sensitivity, specificity, and positive predictive value.” Tablet audiometry also scored similarly to sound-booth testing in terms of perceived usability. The tablet-based test also fared better than sound-booth audiometry in terms of the users’ intention to use and promote.
“Key to preventing disabling hearing loss is an ability to perform efficient audiometric monitoring and early ototoxicity identification to enable an antimicrobial prescribing change if possible,” the authors noted, citing a previous research that found ototoxic effects even from a single course of aminoglycosides.
Shah explained that early detection of hearing damage can help CF patients make new decisions with their doctor. “Although further longitudinal analysis is required to validate tablet-based audiometry within ototoxicity monitoring programs, we highlight a case where the use of tablet-based audiometry was able to detect significant asymptomatic ototoxicity at extended high frequencies during aminoglycoside administration. This importantly allows the clinician to have an informed discussion with the individual and consider alternative antimicrobial options.”
Current pandemic restrictions underscore the importance of telehealth tools in audiology, and how they might be mainstreamed in the new normal. These tools include tablet or smartphone systems that can be used by patients in their homes. “The current COVID-19 pandemic has really highlighted the difficulties with sound-booth audiometry with a drive for telehealth options,” said Shah. “At present, tablet-based audiometry is performed by health professionals within a ward or outpatient-based setting but can still enable a more streamlined ototoxicity monitoring solution.”
The authors also found that web-based hearing tests completed on participants’ personal computers yielded less ideal results than those using tablet audiometry. “Although web-based audiometry had high specificity, given the limited frequencies tested, it had poor sensitivity and negative predictive value,” they noted.
The authors said that the web-based tests were done using off-the-shelf earphones in uncontrolled environments that possibly had noise at limited frequencies. “The development of low-cost insert earphones suitable for extended high-frequency audiometry may increase reliability,” they added.
Shah expects that home-based screening tools will soon improve. “Moving forward, there will be a drive to create and validate accurate home-based audiometric screening solutions in highly susceptible cohorts.” A more salient recommendation in the study was an algorithm charting how cystic fibrosis patient care can include an ototoxicity monitoring program that uses tablet audiometry. The tablet-based tool can be used for hearing screening, repeat tests, and change monitoring along the course of CF treatment.