Suboptimal usage of hearing aids in adults with hearing loss: Singapore audiologists’ perspective and current practice

INTRODUCTION Hearing aid (HA) is the treatment of choice to reverse functional decline for the majority of hard-of-hearing individuals. Singapore has a fast-ageing population, and according to statistics from Singapore National Health Survey 2010,[1] nearly 10% of Singapore adult residents aged 60–69 years have disabling hearing loss (HL), defined by World Health Organization (WHO) as HL severity ≥40 decibel (dB) in the better hearing ear.[2] Despite the psychosocial consequences of HL and technological advances of HA, only 3.3% of adults[1] and 7.5% of older adults in nursing homes[3] with HL use HA. From 2004 to 2013, despite a positive trend in HA uptake in Singapore, HA usage remained suboptimal.[4] The introduction of government-subsidised HA through the ‘senior mobility fund’ in 2014 has further improved HA acquisition, but not usage compliance.[5] Audiological practice is relatively new in Singapore, with the first hospital audiology unit established in 1977. Audiology training started only in 2013, with 40 graduates to date from the 2-year postgraduate audiology programme at the National University of Singapore. Based on the known number of audiologists in Singapore, we estimated the current ratio of audiologists to the Singapore population to be around 1:46,868, in contrast to more favourable ratios in Canada (1:20,555) and New Zealand (1:11,918).[6] The Society for Audiology Professionals Singapore (SAPS) was established in 2000 to represent the professional interest of audiologists. The SAP published the Best Practice Guidelines – Management of Adult Hearing Loss with Hearing Amplification[7] in 2019 to decrease variability in service delivery and increase the probability of patient satisfaction. This document was heavily influenced by best practices guidelines from Australia and the USA.[8,9] We hypothesised that there is currently significant variability in audiological practice in Singapore, which the SAPS guidelines attempted to address. In this study, the first of its kind in Singapore, we aimed to explore the current audiological practice landscape for audiologists managing adult patients with HL. Other objectives included determining the level of consensus in the definition of disabling HL and successful hearing treatment outcome for hard-of-hearing adult patients, as well as providing a profile of suboptimal adult HA users in Singapore. METHODS This was a prospective cross-sectional study of Singapore audiologists conducted using a self-administered online questionnaire between December 2020 and August 2021. This study was approved by the National Healthcare Group Domain Specific Review Board (DSRB reference: 2019/01180). All audiologist members of SAPS were invited to participate in the study if they fulfilled the main inclusion criterion — practising primarily in adult hearing rehabilitation. The SAPS members whose scope of work did not include aural rehabilitation of hard-of-hearing adults and elderly patients (e.g. paediatric audiologists, sales employees of HA manufacturers) were excluded. It was estimated that approximately half of the 120 SAPS members were eligible for the study. The questionnaire was kept anonymous to encourage honest answers. A 21-question questionnaire was developed by the investigators and administered using Google Form. Three study domains, excluding participant demographics, were probed. The domains were definition of hearing treatment success (four questions), current practice (14 questions) and profiling of patients who reported suboptimal HA usage (three questions). The survey was piloted on three audiologists working in Singapore hospitals to test for understandability, and face and content validity. Construct validity was established through high relevance of the questions. Internal consistency was checked among different questions that probe the same domain. Responses were transferred to Microsoft Excel, and descriptive statistics were reported. RESULTS Fifty audiologists responded to the survey — two-thirds were from government hospitals and the rest were in private practice. Of the 50 respondents, 4% owned their practices and 96% were employees, 66% were female, 96% were aged <50 years and had a mean clinical experience of 8 (standard deviation [SD] 6.2) years. Perspective on hearing treatment success Fifty-six percent of the respondents agreed with WHO’s definition of disabling HL. Of the remaining 44% of respondents, half each adopted either a lower dB cut-off (25–35 dB) or a higher dB cut-off (45–50 dB). All respondents agreed that disabling HL can be treated with hearing rehabilitation through long-term, regular HA usage to overcome, reduce or prevent the functional disability and handicap of hearing impairment. All respondents also agreed that HA usage can be considered successful when a person with hearing impairment wears HA on a regular basis and reports benefit from it. Half of the respondents felt that patients with dementia were less likely to be successful first-time HA users, but two-thirds also observed that patients who were already regular HA users will likely continue to do so, even if they develop dementia subsequently. When presented with a classic case of presbycusis [see Supplemental Digital Appendix at https://links.lww.com/SGMJ/A77], most respondents (86%) agreed that the patient should demonstrate a strong level of self-efficacy in using his/her HA. Also, 84% of the respondents agreed that the patient should benefit from using validated hearing outcome measures. When considering data-logging as evidence of successful treatment, 58% of the respondents considered ≥6–8 h/day and 24% considered ≥9 h/day of HA usage to be evidence of success. Although Singapore audiologists concurred on the definition of successful hearing treatment [Table 1], there were considerable differences in how disabling HL should be defined and how hearing treatment success should be measured. However, 94% of the respondents agreed that ≤2 h of daily HA usage are a strong indicator of poor usage.Table 1: Definitions of successful hearing treatment and hearing diagnostic tools usage in adult patients.Current clinical practice Respondents were asked to select up to three diagnostic evaluations they could perform before recommending amplification to their patient [Table 1]. Pure-tone audiometry (PTA 100%) was universally preferred, followed by word recognition scores (WRS 82%) and aided functional gain test (30%). Patient’s speech-in-noise (SiN) performance (e.g., QuickSIN) was selected by 20% of the respondents. Half of the respondents (52%) reported using hearing-specific patient-reported outcome measures (PROMs), with 35% (9/26) using PROMs at least 61% of the time and 65% (17/26) using PROMs less frequently. Only three and 16 audiologists reported using PROMs before and after HA fitting, respectively. Client-oriented scale of improvement was the most preferred (n = 24) PROM, followed by the hearing handicap inventory for adults/elderly screening version (n = 13) and the international outcome inventory for HA (n = 11). Of the 56% of respondents who would perform real-ear measurements (REM) to verify HA real-ear performance, most would perform this verification less than 40% of the time. Sixteen respondents felt that REM was time-consuming and poorly accepted or tolerated by patients, while 11 respondents stated either having no or limited access to REM equipment. Nine respondents would use alternative tests such as unaided versus aided functional gain test, or speech audiometry to verify the settings of HA. Profile of poor HA usage Most respondents (98%) had encountered patients who were poor HA users; 60% and 40% of respondents reported that at least one in five and at least two in five of their patients were poor HA users, respectively. Twelve out of 34 potential patient factors for poor HA usage were identified by ≥50% of respondents as important contributing factors [Table 2]. Patient’s psychosocial belief of HL and HA (98%), the lack of caregiver support (98%) and having hearing difficulties in background noise (74%) were ranked as the three most impactful factors that influence hearing treatment outcome. Overall, 56% of the respondents indicated patient’s advancing age as an important factor for HA non-usage, while 76% of respondents reported that a higher proportion of suboptimal HA usage occurs in patients aged ≥66 years [Table 2].Table 2: Patient factors for suboptimal usage of hearing aid.Patient-centred hearing care Respondents were asked to rank 12 care delivery techniques they would use to improve patient’s outcome and satisfaction during hearing treatment. Respondents were blinded to the two classifications of the techniques, ‘patient-centred’ model of care (PCC) or the traditional ‘biomedical’ service delivery.[10] Majority of respondents preferred the PCC approach in their clinical practices [Table 3], while 94% of respondents reported that they found these techniques useful when it came to improving their patient’s HA usage.Table 3: Patient-centred care model.DISCUSSION There was good consensus on the definition of good hearing treatment outcome, although considerable differences were noted on the definition of disabling HL for adult patients and how treatment success should be measured [Table 1]. While the hours of usage of HA is a relatively easy parameter to determine, such data are not the only observable traits of a successful HA outcome [Table 2]. This discussion will focus on selected factors that were deemed impactful by the majority of respondents towards achieving successful hearing treatment outcome. This study identified patient’s psychosocial belief of HL and HA as the most important factor that impacted hearing treatment outcome. Research on health behaviour theories has confirmed that attitudes and beliefs are associated with future HA uptake and compliance.[11] A recent study had measured the psychosocial beliefs of a group of ‘adherent’ versus a group of ‘non-adherent’ elderly HL patients and concluded that the two groups differed primarily in their perception regarding communication difficulties and their expectations about HAs.[12] This implies that audiologists can reshape the HA-uptake behaviour of elderly patients through effective counselling and education. Further local behavioural studies that combine quantitative and qualitative research methodologies will help audiologists in their education and counselling strategies. For patients with poor self-efficacy in daily living, the lack of family/caregiver’s support was found to impact successful hearing treatment outcome. Most respondents agreed that patients’ self-efficacy in using their own HA is an important indicator of a successful hearing treatment. Self-efficacy generally refers to patient’s confidence and ability to use, care for and manage all aspects of what HA ownership entails.[13] In the absence of self-efficacy (e.g., dementia patients), audiologists felt that HA success quickly degrades to a 50–50 proposition. This sentiment concurs with previous research correlating successful HA use with patients’ cognitive function.[14] It was reassuring that most audiologists witnessed that patients can continue to be efficacious with their HA when fitted early, even if cognitive impairment sets in eventually. Recent studies have established HL as a strong risk factor for dementia.[15] Despite two-thirds of audiologists agreeing that cognitive ability is important in hearing treatment outcome, cognitive screening is currently not part of hearing evaluation. Cognitive evaluation may be considered only when patients or caregivers express concerns about potential cognitive decline. Due to the close association of ageing, HL and dementia, and considering the ageing population phenomenon in Singapore and the developed world, there should be careful considerations for cognitive screening to be included as part of hearing evaluation. Supportive roles of family/caregiver’s involvement could include helping the patient to remember or understand the information provided by the audiologist during consultation, understanding the problems that HL had caused, and finding the communication strategies that would be needed. At home, it is useful to have someone familiar to the patient to help manage the upkeep of the HA and remind the patient to put on his/her HA while ensuring proper placement in the patient’s ears, especially for patients who have poor finger dexterity or vision and those with difficulty remembering. A family member’s positive and supportive attitude towards a patient would help translate motivation into the act of putting on his/her HA. Therefore, rehabilitative intervention to support HA use should consider the formal involvement of family members and caregivers. Speech listening in background noise was found to impact hearing treatment outcome. The underlying structural dysfunction to an ageing brain could cause age-related SiN performance decline.[16] This problem persists despite noise reduction features in modern HAs.[17] A recent local study reported that the most common outcome after HA fitting was a reduction, rather than an absence of difficulties hearing in noise,[18] which is crucial in managing expectation. Patient’s SiN performance should be clinically assessed before HA fitting. The most preferred hearing diagnostic assessment was PTA, followed by WRS in quiet. It is concerning that only a fifth of audiologists have listed SiN as a pre-HA fitting evaluation, as normal SiN performance cannot be assumed despite normal audiograms or WRS scores.[19] Real ear measurement-assisted HA fitting was not routinely used by most audiologists for HA verification. Many respondents opined that REM procedure is time-consuming, with no guarantee that patients can tolerate or accept the procedure, while others had limited access to REM equipment. A recent systematic review on the effectiveness of REM found that REM-assisted HA fitting provided statistically significant advantage over manufacturer’s first-fit algorithms and improved speech intelligibility in noise;[20] however, the review also rightly called for more studies to demonstrate cost-effectiveness as a way to justify wider adoption. Finally, this study found that most Singapore audiologists lean towards PCC approaches when managing adult patients. Patient-centredness is becoming the core value of health services worldwide.[21] The use of evidence-based clinical evaluations to screen, diagnose and fit adult patients with HA, together with the use of patient-level outcome measures to demonstrate clear benefits and validate care outcome, would be a powerful step towards audiological clinical practice that follows the PCC model. Patient’s perspective of his/her hearing health is a core component of evidence-based audiological practice and PCC. Subjective health constructs such as listening effort, participation, self-efficacy and psychosocial functioning could be captured by applying appropriate PROMs to bridge the gap between audiologists’ perception and real-world patient’s benefit.[22] Despite this emphasis, it was surprising that few quality of life (QOL)-based outcome measurements are used in practice. It is worth noting that selecting the QOL instruments that address sensory loss, communication, participation, distress, depression and anxiety (e.g., Health Utilities Index Mark 3, WHO Disability Assessment Schedule 2.0) is essential for assessing hard-of-hearing individuals and could be used to form a strong basis for HA intervention during counselling. Other generic QOL measures, such as 36-item short form survey and 5-level EuroQol that lack specificity and sensitivity in assessing the impact of HL on QOL, should be avoided.[23] Although 88% of respondents felt that it was necessary to use PROMs to validate hearing treatment outcomes, the returns on some outcome measures were less than half of the surveyed population. This reflects a general sentiment of low usage of PROMs across the surveyed population and begs the question of whether such outcome measures are not useful or onerous to use in local clinical practice. Ideally, PROMs should have been formally translated and culturally adapted for local populations. There is currently no concerted effort to develop, translate, validate or culturally adapt hearing-specific PROMs for use in a multicultural and multilingual Asian society. We postulated that this could be one of the contributing factors that discourages local audiologists from using PROMs. This study has provided valuable insights into suboptimal HA usage and current adult audiological practices in Singapore. Further research is necessary to reconcile any gaps between ‘theoretical best’ and ‘real-world’ practices. It should be noted that this study cannot confirm if the reported practices represented individual preference or organisational workflows and protocols. In the latter case, patient volume, workforce, consultation time and equipment limitations are likely to override autonomous clinical practice choices. These variations may be symptomatic of the relative shortage of audiologists in Singapore, with consequent time limitations, rather than individual practice preference. Acknowledgement Special appreciation and gratitude to all the hardworking audiologists who have participated in this survey. We would like to express our sincere gratitude to SAPS for its invaluable help in sharing the survey with its members. We also wish to thank the three audiologists who volunteered their help to develop the survey. Financial support and sponsorship This work was supported by Tan Tock Seng Hospital (TTSH) under the Pitch-For-Fund Program (PFFP20-13). Conflicts of interest There are no conflicts of interest.

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