By Garrett Thompson, AuD
Recall in Part 1 of this series that two underlying fears of many audiologists regarding the creation of a new category of products called OTCs were brought to the surface. Part 2 continues to poke around at the data as it relates to OTC hearing devices.
Study #1
In a placebo-controlled double-blind randomized clinical trial, Humes et al. (2017) investigated the efficacy of hearing aid intervention in older adults comparing three delivery methods: a traditional audiology best practices (AB) model, a consumer decides (CD) model, and a placebo.
The CD model is related to an OTC model, in that the consumer manages the process on her own with no involvement from a professional; but it likely does not actually emulate an OTC consumer process. The study was performed in a clinical setting, where the CD group watched an instructional video and was provided a booklet on the self-fitting process, at which time they were allowed to trial as many as six hearing aids to determine which of three amplification profiles they preferred.
The hearing aids were pre-loaded with four programs of varying gain configurations, of which the participant could self-adjust via volume control after the selection session, if necessary. Although there are similarities to a potential OTC model, the fact that participants could trial up to six devices is likely not realistic for purchasing an OTC device. The CD group was thoroughly tested and monitored in a clinical setting, which could have affected the perception of success of the CD process. Additionally, 42% of potential participants were rejected because they did not meet the mild-to-moderate hearing loss and no middle ear problems selection criteria; in the real world this group would likely not remove themselves from OTC consideration.
As several of these factors are not typical of the way OTC hearing aids are currently dispensed, the ability to generalize this study is somewhat limited.
Participants in this study were 154 adults 53-83 years old with mild to moderate, bilateral, symmetrical, sensorineural hearing loss (SNHL), with no previous experience with hearing aids. Baseline testing was performed before and outcomes measures were obtained at the end of the six week trial. Outcome measures included the Hearing Handicap Inventory for the Elderly (HHIE), the Connected Speech Test (CST), the Profile of Hearing Aid Performance (PHAPglobal), and the Hearing Aid Satisfaction Survey (HASShaf). High-end digital mini-BTE (behind-the-ear) hearing aids were used for all participants. For the placebo group, the HAs were programmed to a zero dB insertion gain acoustical transparence, meaning they provided no amplification whatsoever (there is some debate on this point, Linda Hood recently spoke at AudiologyNOW and mentioned that zero dB of gain for 65 dB input may have in fact added 6-8 dB of gain for soft inputs).
For the AB and CD groups, basic features were enabled including: directional microphones, dynamic feedback suppression, and noise reduction. In the AB group, HAs were programmed to the NAL-NL2 prescriptive formula and matched to targets using Real Ear Measure verification (Humes, et al, 2017).
Results revealed that the audiology (AB) model was significantly better than the consumer (CD) model for improvement in HHIE, PHAPglobal, and HASShaf.
Both the AB and CD models were efficacious, meaning they each showed significant benefit relative to the unaided condition in terms of HHIE, PHABglobal, HASShaf, and CST scores. The authors point out that the CD model yielded only slightly poorer effect sizes than the AB group. Interestingly, even though the placebo intervention was not statistically better than the unaided scores, 39% of participants expressed a desire to keep the placebo devices (Humes, et al, 2017).
Study #2
An earlier pilot study directly compared a simulated OTC model with a traditional hearing healthcare delivery (Tedeschi & Kihm, 2016). This study was designed to determine if individuals can properly self-diagnose and classify their hearing loss, as well as how satisfied they will be with an OTC model and how it compares to the traditional model.
A sample of 29 individuals with self-reported mild-to-moderate hearing loss who are not using HAs or PSAPs were given the opportunity to choose one of several PSAPs that are commercially available. For six weeks they used these devices without professional involvement. Prices of the PSAPs that were offered ranged from $100-$450. Following that period, those who had hearing loss were invited to receive audiology best practice (ABP) intervention for another six weeks which included: a hearing evaluation, counseling, fitting and verification of hearing aids, instructional information, and aftercare services as needed (Tedeschi & Kihm, 2016). Ultimately, 18 individuals participated in this second phase. The design of this study was intended to mimic the sequence of a typical OTC consumer, moving from self-treatment to professional treatment, even if not in a realistic timeline. This design also opens the study up to weaknesses like order effects.
The authors note that of the 29 participants, four of them (13%) were referred to an ENT due to medical or audiological contraindications for hearing aid use; three of these individuals were eventually cleared for hearing aid use and participated in the study. In each phase of the study, participants were asked to evaluate the process twice. To the question of accurate self-diagnosis, 15 of 29 (52%) correctly identified their hearing as mild-to moderate; of those who did so incorrectly, three had normal hearing and eleven had poorer than moderate hearing. Furthermore, only 14 of 29 (48%) correctly identified their hearing loss as unilateral or bilateral.
When comparing the two delivery models in terms of levels of usage, 95% of the audiology (ABP) group used the devices at least a few times a week; in the OTC group 59% of participants used them at least a few times a week. After the six week period, satisfaction with ABP was considerably higher than for OTC devices; 83% were at least somewhat satisfied compared to 48% for the OTC model.
One in three of the ABP group were very satisfied, in the OTC group that number was one in ten. However, 52% of participants reported that the OTC device helped at least some of the time and they would recommend one to a friend; the willingness to recommend hearing aids to a friend is highly correlated to satisfaction (Kochkin, 2007). Also of note is that at the end of the OTC phase, 90% of participants felt that having some assistance from a professional would have been at least somewhat useful when getting used to the device. (Tedeschi & Kihm, 2016).
**Please stay tuned for the next installment of The Young & the RIC-less, where we will continue to examine the evidence for OTC devices.
Garrett Thompson, AuD is a recent graduate of the City University of New York and just completed his externship at the Callier Center of UT-Dallas. He was a national finalist in the 2015 Academy of Doctors of Audiology student business plan competition. His writing has previously been featured in Audiology Today and Audiology Practices. Thompson received a BA in Economics from Boston College. Contact him at [email protected] or @Dr_Audball
One issue that seems to have escaped most researchers, legislators, audiologists and the general public is the long term effectiveness and use of OTC hearing aids. Even in controlled studies, the placebo effect cannot be ignored. Yet how ell OTC hearing aids are accepted and used over a period of time has really not been explored. This might be labeled “the dresser drawer effect”. How many of these self-diagnosed and self-treated individuals are still using their devices after a few months without professional assistance? Proponents of OTC hearing aids are looking only at cost as the only factors in accepting amplification. While cost is a factor, value is an even larger issue. How much value does the self-treated consumer put in the OTC hearing aid after a few months trying to communicate in a difficult listening situation?