External and middle ear effects on infant hearing screening test results

Modelling the cost-effectiveness of a newborn hearing screening programme; usability and pitfalls

OBJECTIVE

The EUSCREEN project concerns the study of European vision and hearing screening programmes. Part of the project was the development of a cost-effectiveness model to analyse such programmes. We describe the development and usability of an online tool to enable stakeholders to design, analyse or modify a newborn hearing screening (NHS) programme.

DESIGN

Data from literature, from existing NHS programmes, and observations by users were used to develop and refine the tool. Required inputs include prevalence of the hearing impairment, test sequence and its timing, attendance, sensitivity, and specificity of each screening step. Outputs include the number of cases detected and the costs of screening and diagnostics.

STUDY SAMPLE

Eleven NHS programmes with reliable data.

RESULTS

Three analyses are presented, exploring the effect of low attendance, number of screening steps, testing in the maternity ward, or screening at a later age, on the benefits and costs of the programme. Knowledge of the epidemiology of a staged screening programme is crucial when using the tool.

CONCLUSIONS

This study presents a tool intended to aid stakeholders to design a new or analyse an existing hearing screening programme in terms of benefits and costs.

Outcomes of newborn hearing screening at an academic secondary level hospital in Johannesburg, South Africa

BACKGROUND

The Health Professions Council of South Africa (HPCSA) issued early hearing detection and intervention guidelines, which has universal newborn hearing screening (UNHS) as one of the important goals. Despite established evidence of the importance of UNHS globally, there has been no mandated formalised and standardised implementation as yet in South Africa.

OBJECTIVES

The aim of this study was to describe the outcomes of newborn hearing screening (NHS) in an academic secondary level hospital in Johannesburg, South Africa.

METHODS

This was a prospective non-experimental feasibility study over a 3-month period, involving conducting hearing screening of 121 neonates. Audiologists conducted a risk factor assessment, otoscopic examinations and distortion product otoacoustic emissions (DPOAEs) screening on each neonate, with follow-up appointments for re-screening and diagnostic audiological assessments for all neonates with refer findings. Data were analysed using STATA intercooled version 11©, through both descriptive and inferential statistics (Fisher's exact test), with significance established where p-values less than 0.05 were considered statistically significant.

RESULTS

Of the 121 neonates screened, the majority (75%) were screened in the first 24 h of life. A high refer rate (47%) of the total sample was found on DPOAE screening. No maternal or neonatal risk factors were found to be significantly associated with refer findings.

CONCLUSION

Findings contribute towards the existing evidence base that raises implications for successful implementation of NHS programmes in public healthcare in South Africa. Screening protocols need to consider the timing of screening, the measures and procedures adopted in the screening protocols, as well as the follow-up strategies.

Comparison of Two-Step Transient Evoked Otoacoustic Emissions and One-Step Automated Auditory Brainstem Response for Universal Newborn Hearing Screening Programs in Remote Areas of China

Objective: To compare the hearing screening results of two-step transient evoked otoacoustic emissions (TEOAE) and one-step automatic auditory brainstem response (AABR) in non-risk newborns, and to explore a more suitable hearing screening protocol for infants discharged within 48 h after birth in remote areas of China. Methods: To analyze the age effect on pass rate for hearing screening, 2005 newborns were divided into three groups according to screening time after birth: <24, 24-48, and 48-72 h. All subjects received TEOAE + AABR test as first hearing screen, and those who failed in any test were rescreened with TEOAE + AABR at 6 weeks after birth. The first screening results of AABR and TEOAE were compared among the three groups. The results of two-step TEOAE screening and one-step AABR screening were compared for newborns who were discharged within 48 h. The time spent on screening was recorded for TEOAE and AABR. Results: The pass rate of TEOAE and AABR increased significantly with the increase of first screening time (P < 0.05), and the false positive rate decreased significantly with the increase of first screening time (P < 0.05). The failure rate of first screening of AABR within 48 h was 7.31%, which was significantly lower than that of TEOAE (9.93%) (P < 0.05). The average time spent on AABR was 12.51 ± 6.36 min, which was significantly higher than that of TEOAE (4.05 ± 1.56 min, P < 0.05). The failure rate of TEOAE two-step screening was 1.59%, which was significantly lower than one-step AABR. Conclusions: Compared with TEOAE, AABR screening within 48 h after birth can reduce the failure rate and false positive rate of first screening. However, compared with TEOAE two-step screening, one-step AABR screening has higher referral rate for audiological diagnosis. In remote areas of China, especially in hospitals with high delivery rate, one-step AABR screening is not feasible, and two-step TEOAE screening protocol is still applicable to UNHS screening as more and more infants discharged within 48 h after birth.

Evidence for a Right-Ear Advantage in Newborn Hearing Screening Results

The aim of the present study was to investigate the effect of ear asymmetry, order of testing, and gender on transient-evoked otoacoustic emission (TEOAE) pass rates and response levels in newborn hearing screening. The screening results of 879 newborns, of whom 387 (study group) passed screening successfully in only one ear in the first TEOAE screening, but passed screening successfully in both ears thereafter, and 492 (control group) who passed screening successfully in both ears in the first TEOAE, were retrospectively examined for pass rates and TEOAE characteristics. Results indicated a right-ear advantage, as manifested by significantly higher pass rates in the right ear (61% and 39% for right and left ears, respectively) in the study group, and in 1.75 dB greater TEOAE response amplitudes in the control group. The right-ear advantage was enhanced when the first tested ear was the right ear (76%). When the left ear was tested first, pass rates were comparable in both ears. The right-ear advantage in pass rates was similar in females versus males, but manifested in 1.5 dB higher response amplitudes in females compared with males, regardless of the tested ear and order of testing in both study and control groups. The study provides further evidence for the functional lateralization of the auditory system at the cochlear level already apparent soon after birth in both males and females. While order of testing plays a significant role in the asymmetry in pass rates, the innate right-ear advantage seems to be a more dominant contributor.

Diagnosis and Management of Congenital Sensorineural Hearing Loss

Hearing loss is the most common sensory disorder in the USA. The diagnosis of congenital hearing loss starts with newborn hearing screening, which is best performed with auditory brainstem evoked responses in order to avoid the risk of missing auditory neuropathy spectrum disorder. A careful history and physical exam can occasionally help reveal the etiology for congenital hearing loss. Imaging studies, either CT temporal bones or MRI of the internal auditory canals without gadolinium, and genetic testing, in particular for connexin 26, connexin 30, and Pendred syndrome, are the most useful diagnostic tests. Management of congenital hearing loss involves early fitting of amplification. Early cochlear implantation, preferably before 2 years of age, should be strongly considered for children with bilateral severe hearing loss.

[Newborn Hearing Screening and Subsequent Diagnostic Evaluation: Analysis and Outcomes of 6,063 Infants Born in a Community Hospital]

A retrospective study was conducted to examine the implementation status of newborn hearing screening (NHS) of 6,063 infants born in a single community hospital in Japan between 2005 and 2013. An automated auditory brainstem response device was used for NHS and an auditory brainstem response was mainly used for further diagnostic evaluation. Although the participation rate in the NHS was 88.8% in 2013, increasing year by year, it failed to reach 100% probably because NHS is a charged option under the current Japanese healthcare system. Among 40 (0.66%) infants who finally failed their NHS, 34 were referred for subsequent diagnostic evaluation and the remaining 6 were lost to follow-up. Thirty-one of these 34 were diagnosed as having hearing impairment and 3 (0.05%) were identified as having normal hearing, which is considered as a false positive. Both the final referral rate and the hearing impairment rate were significantly higher in the high-risk than in the low-risk group. Compared to the previous national report, the rate of bilateral hearing impairment (0.33%) was significantly higher in this study. Ten (38.5%) out of 26 in the high-risk group were most often diagnosed with otitis media with effusion (OME), while 4 (50%) out of 8 in the low-risk group were diagnosed as having sensorineural hearing loss. Seven (35%) out of 20 with bilateral hearing impairment attained a normal hearing level at a median age of 18 months. Although the primary aim of NHS is early detection of congenital permanent hearing loss, OME is observed commonly in NHS-failed infants. It is therefore important to examine the middle ear status carefully as part of the diagnostic evaluation. Thirty-four infants underwent further diagnostic evaluation at a median age of 46 days, and hearing aids were given in 10 of them at a median age of 5.6 months without delay. Because high-risk patients often tend to be lost to follow-up, otolaryngologists have to give a detailed explanation to caregivers and to build a solid support system for children with hearing impairment.

Effect of age on click-evoked otoacoustic emission: A systematic review

OBJECTIVE:

The aims of this study were to investigate the changes of the total intensity of transient evoked otoacoustic emission (TEOAE) and signal-to-noise ratio in various frequency bands as a function of aging, and to explore the role of age-related decline of cochlear outer hair cells.

DATA SOURCES:

The literature was searched using the PubMed database using ‘transient-evoked otoacoustic emissions’ as a keyword. Articles were limited as follows: Species was ‘Humans’; languages were ‘English and Chinese’; publication date between 1990-01-01 and 2010-12-31. The references of the found were also searched to obtain additional articles.

DATA SELECTION:

Inclusion criteria: (1) Articles should involve the total TEOAE level or signal-to-noise ratio. (2) The measurement and analysis system used was Otodynamics ILO analysis system (ILO88, ILO92, ILO96 or ILO292). (3) Studies involved groups of greater than 10 subjects and TEOAE results were from normally hearing ears. (4) If more papers from the same author or laboratory analyzed the same subjects, only one was used.

MAIN OUTCOME MEASURES:

The correlations of the age scale with the total level and signal-to-noise ratio of TEOAE was determined, respectively.

RESULTS:

(1) TEOAE total level gradually increased until 2 months of age, and then decreased with increasing age. Significant negative correlations between total TEOAE level and age were found (r = –0.885, P = 0.000). (2) The most rapid decrease of TEOAE amplitude occurred at 1 year old. The total TEOAE level decreased about 4.25 dB SPL between 2 months to 1 year old, then about 0.26–0.52 dB SPL from 1 year to 10 years old, about 0.23 dB SPL from 11 years to 25 years old, and about 0.14 dB SPL from 26 years to 60 years old. (3) The signal-to-noise ratio in the frequency bands centered at 1.5, 2, 3 and 4 kHz decreased with increasing age after 2 months of age. Significant negative correlations between the signal-to-noise ratio and age were found for frequency bands ranging from 1.5 kHz to 4 kHz, with the highest correlations at 4 kHz (r = –0.890, P < 0.01), then at 3 kHz (r = –0.889, P < 0.01), at 2 kHz (r = –0.850, P < 0.01) and at 1.5 kHz (r = –0.705, P < 0.05). Conversely, a positive correlation between the signal-to-noise ratio centered at 1 kHz and age was found, but was not statistically significant (r = 0.298, P = 0.374).

CONCLUSION:

The total TEOAE response level decreased with increasing age after the first 2 months of age. The signal-to-noise ratio also decreased with increasing age in frequency bands above 1.5 kHz. The signal-to-noise ratio in higher frequencies decreased faster than in lower frequencies, leading to the maximum signal-to-noise ratio shift form 3.2–4.0 kHz in neonates to 1.5 kHz in adults, and further decreasing the total TEOAE response level. The age-related TEOAE spectrum peak shift is most likely because the outer hair cells functioning in higher frequencies are more prone to damage than those for lower frequencies.

Sound-conduction effects on distortion-product otoacoustic emission screening outcomes in newborn infants: test performance of wideband acoustic transfer functions and 1-kHz tympanometry

OBJECTIVE

Universal newborn hearing screening (UNHS) test outcomes can be influenced by conditions affecting the sound conduction pathway, including ear canal and/or middle ear function. The purpose of this study was to evaluate the test performance of wideband (WB) acoustic transfer functions and 1-kHz tympanometry in terms of their ability to predict the status of the sound conduction pathway for ears that passed or were referred in a UNHS program.

DESIGN

A distortion-product otoacoustic emission (DPOAE) test was used to determine the UNHS status of 455 infant ears (375 passed and 80 referred). WB and 1-kHz tests were performed immediately after the infant's first DPOAE test (day 1). Of the 80 infants referred on day 1, 67 infants were evaluated again after a second UNHS DPOAE test the next day (day 2). WB data were acquired under ambient and tympanometric (pressurized) ear canal conditions. Clinical decision theory analysis was used to assess the test performance of WB and 1-kHz tests in terms of their ability to classify ears that passed or were referred, using DPOAE UNHS test outcomes as the "gold standard." Specifically, performance was assessed using previously published measurement criteria and a maximum-likelihood procedure for 1-kHz tympanometry and WB measurements, respectively.

RESULTS

For measurements from day 1, the highest area under the receiver operating characteristic curve was 0.87 for an ambient WB test predictor. The highest area under the receiver operating characteristic curve among several variables derived from 1-kHz tympanometry was 0.75. In general, ears that passed the DPOAE UNHS test had higher energy absorbance compared with those that were referred, indicating that infants who passed the DPOAE UNHS had a more acoustically efficient conductive pathway.

CONCLUSIONS

Results showed that (1) WB tests had better performance in classifying UNHS DPOAE outcomes than 1-kHz tympanometry; (2) WB tests provide data to suggest that many UNHS referrals are a consequence of transient conditions affecting the sound conduction pathway; (3) WB data reveal changes in sound conduction during the first 2 days of life; and (4) because WB measurements used in the present study are objective and quick it may be feasible to consider implementing such measurements in conjunction with UNHS programs.

Early hearing screening: what is the best strategy?

OBJECTIVES

A discussion concerning the relevance of universal newborn hearing screening has been conducted in France since the end of the 1990s. As a contribution to the choice of strategy to be implemented, we evaluated and compared the results of this screening and its impact on the parent-infant relationship as a function of the time at which screening was performed: during the infant's stay in the maternity unit, in the first strategy (strategy 1), or 2 months after birth, in the second strategy (strategy 2).

PATIENTS AND METHOD

Five thousand seven hundred and ninety infants participated in the study: 3202 were included in the first strategy and 2588 were included in the second strategy. Within this population, 143 mother-infant pairs were submitted to psychological assessment. We compared the number of infants screened, the number of first positive tests, the number of false-positive tests and the number of infants not reviewed after screening. Adverse effects on the parent-infant relationship were evaluated in terms of maternal anxiety and the quality of early interactions.

RESULTS

A statistically significant difference in favor of newborn screening was demonstrated for the number of infants screened: 95.72% for the first strategy [95.0%; 96.4%], 64.18% for the second strategy [62.3%; 66.0%]; the number of first positive tests: 1.11% during newborn screening [0.7%; 1.5%], 3.13% in the second strategy [2.3%; 4.0%]; the number of false-positive tests: 0.29% in the first strategy [0.10%; 0.49%] and 2.65% in the second strategy [1.88%; 3.42%]; and the number of infants not reviewed after screening: 8.8% during newborn screening [0.0%; 18.4%] and 38.5% in the second strategy [25.2%; 51.7%]. Analysis of the results of the psychological assessment showed that screening per se did not have any impact on maternal anxiety or on the quality of early interactions, regardless of the screening strategy used. However, the result of the test had a significant impact. Announcement of a positive result increased maternal anxiety and induced a deterioration of the mother's psychological state which affected the quality of early interactions. As the number of positive results is significantly lower in newborn hearing screening, there are consequently fewer psychological side effects with this strategy than with the second strategy.

CONCLUSION

This study demonstrates that universal newborn hearing screening is the most efficient strategy.