Study: Screening for Hearing Loss in CF Patients Feasible With Tablet-based Tests
Tablet-based hearing tests can accurately screen for hearing loss in people with chronic lung diseases such as cystic fibrosis (CF) without specialist supervision, according to a recent study.
This finding suggests that tablets may be an inexpensive and practical addition to programs that monitor patients for signs of hearing loss.
The study, “Tablet and web-based audiometry to screen for hearing loss in adults with cystic fibrosis,” was published in the journal Thorax.
Life-threatening bacterial infections are common among patients with chronic lung diseases such as CF, bronchiectasis, and chronic obstructive pulmonary disease. When caused by certain microbes known as gram-negative bacteria, patients often are prescribed repeated treatments with aminoglycoside antimicrobial medicines, such as azithromycin, which can lead to hearing loss — a process referred to as ototoxicity (also known as “ear poisoning”).
Hearing loss can be minimized through early detection of its symptoms, but developing effective outpatient programs to monitor for these presents challenges.
Conducting a hearing test — audiometry — in a sound booth, for instance, is costly, time-consuming, and requires a trained audiologist. It also is an impractical way to regularly test large groups of patients, particularly in resource-poor countries.
To address this challenge, a team led by researchers from the Royal Brompton and Harefield NHS Foundation Trust, in the U.K., analyzed the accuracy of tablet and web-based hearing tests. These tests could be performed by non-specialists in outpatient settings.
The investigators recruited 126 CF patients, median age of 31.5 years, to conduct a series of web- and tablet-based hearing tests. The web-based hearing test took place on a personal computer, using standard earphones or headphones. This test measured frequencies between 0.5 and four kilohertz (kHz).
Web- and tablet-based results were compared to those from a hearing booth, performed at an audiology clinic. Both the tablet and hearing booth analyzed frequencies between 0.25 and 12 kHz.
Overall, 45% of the group (57 participants) showed hearing loss in the sound booth test. Sensorineural hearing loss, caused by defects in the inner ear, was the most common. Conductive defects, affecting the outer and middle ear, accounted for 5% of hearing loss; 9% had mixed causes.
Ten participants had hearing loss in the frequency range critical for speech recognition (0.5 to 4 kHz), suggesting that their hearing loss likely affected their quality of life.
Both age and time spent on intravenous antimicrobial therapy correlated with an increased risk of hearing loss in this group, although the researchers pointed out that older patients are more likely to experience an overall longer course of therapy.
Results from the tablet-based test correlated well with those from the hearing booth. The tablet test correctly detected most cases of hearing loss (high test sensitivity) and it proved to be especially accurate in detecting instances of no hear loss (high test specificity).
“Tablet audiometry had good usability, was 93% sensitive, 88% specific with 94% negative predictive value to screen for hearing loss compared with web self-test audiometry and questionnaires which had poor sensitivity,” researchers wrote.
Although the web-based test proved better at accurately identifying patients who truly had hearing loss, it was less sensitive overall and more likely than the tablet-based test to identify a patient as not having hearing loss when, in actuality, they did.
Both tests outperformed the Hearing Handicap Inventory for Adults questionnaire — a standard self-reported measure of hearing loss — across nearly all measures.
Furthermore, tablet-based tests were associated with a good user experience, with participants reporting a high preference for them, followed by the booth-based and web-based formats.
The researchers calculated that the tablet provided an economical way to monitor patients for signs of hearing loss related to antimicrobial use. They estimated that the cost for monitoring of approximately 500 patients by tablet to be half that of the booth-test, roughly £40,000 ($51,432) per year vs. £80,000 ($102,864).
“Our study highlights the significant [hearing-related] impact of antimicrobial prescribing in adults with CF, and presents data highlighting the applicability of tablet-based audiometry as a practical screening tool with high accuracy that can be used within integrated ototoxicity monitoring programmes in chronic lung disease to identify ototoxicity at an early stage,” the team concluded.