Abstract:
Hearing loss is a serious disability that not only affects the individual and the family
but also places a heavy burden on resources of communities and countries. Access
to hearing care is unfortunately limited and services are often reserved for tertiary
and secondary hospitals, universities and practices in the private sector. This project
aimed to determine approaches that could be used to detect hearing loss accurately
and affordably in primary health care clinics. More specifically, the project evaluated
the performance of low-cost, smartphone-based hearing screening at primary health
care clinics. The project also investigated the performance of hearing screening
using self-reported hearing loss and pure tone audiometry in primary health care
clinics. Furthermore, the project aimed to determine the prevalence of hearing
disorders in patients three years of age and older, as well as the nature and
characteristics of hearing disorders found at primary health care clinics. The project
aimed to provide research-based recommendations for clinical practice of hearing
detection at primary health care clinics.
Nonprobability purposive sampling was used at both primary health care clinics to
evaluate the performance of low-cost, smartphone-based hearing screening. 1236 participants were included in the final analysis and participants were screened using
the hearScreen™ application following a two-step screening protocol and diagnostic
pure tone audiometry to confirm hearing status. Sensitivity and specificity for
smartphone screening was 81.7% and 83.1% respectively. Gender [2(1, N=126)=
.304, p>.05] and race [2(1, N=126) = .169, p>.05)] had no significant effect on
screening outcome for children whilst for adults age (p<0.01; .04) and gender
(p=0.02; -.53) had a significant effect on screening outcomes with males more
likely to fail. Initial screening test times were less than a minute (48.8s ± 20.8 SD) for
adults and slightly more than a minute for children (73.9s ± 44.5 SD). The
hearScreen™ smartphone application provides time-efficient identification of hearing
loss with adequate sensitivity and specificity for accurate testing at primary health
care settings.
To evaluate the performance of self-reported hearing loss in isolation, and a
combination of self-reported hearing loss and pure tone audiometry screenings in
primary health care clinics in South Africa, nonprobability purposive sampling was
used at both primary health care clinics and 1084 participants were included. It was
found that 40.2% self-reported a hearing loss with no significant association with
gender or race. Self-reported hearing loss increased significantly with increasing
age. A hundred and thirty six participants (12.5%) self-reported hearing loss and
failed audiometry screening (35 dB HL at 1, 2 and 4 kHz). Combining self-report with
a second stage audiometry screening revealed a high test accuracy (81.0%) for
hearing loss, was the most accurate procedure (86.1%) for the identification of high
frequency hearing loss. Whilst self-report of hearing loss is an easy and time-efficient screening method to
use at primary health care clinics, its accuracy may be limited when used in isolation
and it may not be sufficiently sensitive to detect hearing loss. Combining a simple
audiometry screening as a second-stage screen can significantly improve overall
performance and efficiency of the screening protocol.
To determine the prevalence of hearing disorders, a cross-sectional design was
used in patients three years of age and older attending two primary health care
clinics. Nonprobability purposive sampling was used and 1236 participants were
screened. It was found that the hearing loss prevalence was 17.5% across both
clinics. Furthermore, most hearing losses were bilateral (70.0%) and were of a
sensorineural nature (84.2%). Participants 40 years and older were at significantly
higher risk for hearing loss.
Decentralizing hearing services to primary health care clinics could alleviate negative
effects and high expenses usually experienced due to hearing loss. Using selfreported
hearing loss in combination with smartphone technology provides the
possibility to expand and decentralize hearing care services to primary health care
level. Furthermore, prevalence data suggests that 17.5% of people present with
some form of hearing loss. These findings provide valuable baseline data to motivate
for the inclusion of hearing care at primary health care clinics. Furthermore, these
findings provide baseline data to plan and identify specific program goals and
specification of care pathways to support implementation of sustainable hearing
services across primary health care clinics in South Africa.