Progress towards early detection services for infants with hearing loss in developing countries

Community-based infant hearing screening in a developing country: parental uptake of follow-up services

Background

Universal newborn hearing screening is now considered an essential public health care for the early detection of disabling life-long childhood hearing impairment globally. However, like any health interventions in early childhood, parental support and participation is essential for achieving satisfactory uptake of services. This study set out to determine maternal/infant socio-demographic factors associated with follow-up compliance in community-based infant hearing screening programmes in a developing country.

Methods

After health educational/counselling sessions, infants attending routine childhood immunisation clinics at four primary care centres were enrolled into a two-stage infant hearing screening programme consisting of a first-stage screening with transient-evoked otoacoustic emissions and second-stage screening with automated auditory brainstem response. Infants referred after the second-stage screening were scheduled for diagnostic evaluation within three months. Maternal and infant factors associated with completion of the hearing screening protocol were determined with multivariable logistic regression analysis.

Results

No mother declined participation during the study period. A total of 285 out of 2,003 eligible infants were referred after the first-stage screening out of which 148 (51.9%) did not return for the second-stage, while 32 (39.0%) of the 82 infants scheduled for diagnostic evaluation defaulted. Mothers who delivered outside hospitals were significantly more likely to return for follow-up screening than those who delivered in hospitals (Odds ratio: 1.62; 95% confidence intervals: 0.98 – 2.70; p = 0.062). No other factors correlated with follow-up compliance for screening and diagnostic services.

Conclusion

Place of delivery was the only factor that correlated albeit marginally with infant hearing screening compliance in this population. The likely influence of issues such as the number of return visits for follow-up services, ineffective tracking system and the prevailing unfavourable cultural perception towards childhood deafness on non-compliance independently or through these factors warrant further investigation.

Infant hearing loss in South Africa: age of intervention and parental needs for support

Hearing loss is referred to as the silent, overlooked epidemic in developing countries, and data reporting the mean age of diagnosis and intervention is virtually non-existent due to limited systematic or routine screening programs. The objective of this paper is to present findings of recent practice in early diagnosis and intervention services in an urban South African context, with specific reference to parental needs for support. Data was collected by means of questionnaire surveys for 54 parents of children with congenital or early-onset hearing loss, followed by focus group discussions conducted with 10 parents. The results of this study indicate the mean age of diagnosis to be 23 months (+/-18 SD), the mean age of initial hearing-aid fitting to be 28 months (+/-19 SD), and the mean age of enrollment into an early intervention program to be 31 months (+/-19 SD). In addition, results signify that this diverse and challenging population of parents of young hearing-impaired children largely depends on the ongoing support, guidance, and commitment of the pediatric audiologist.

Sentimentos manifestados por mães frente à triagem auditiva neonatal

OBJETIVOS: identificar os sentimentos das mães em relação à Triagem Auditiva Neonatal (TAN) durante a testagem de seu filho; verificar a suficiência de informações prestadas sobre o tema; conhecer sua opinião quanto à possibilidade de o filho apresentar deficiência auditiva. MÉTODOS: durante três meses foram entrevistadas 75 mães de crianças nascidas no Hospital Universitário de Santa Maria, que compareceram, para realização da Triagem Auditiva Opcional. Foram prestadas informações sobre objetivos e procedimentos da TAN e ressaltada a importância do retorno da criança entre oito e 12 meses de idade. Foi aplicado um questionário de forma individual por graduandos em Fonoaudiologia, relacionado aos objetivos da pesquisa. RESULTADOS: 58 (77,3%) mães afirmaram que a TAN é uma maneira de identificar a deficiência auditiva cedo; 64 (85,3%) consideraram suficientes as informações recebidas; 27 (36%) referiram sentimentos positivos enquanto o filho está sendo avaliado, 23 (30,7%) apontaram sentimentos negativos e 25 (33,3%) sentimentos mistos (tanto negativos quanto positivos). Quanto à possibilidade de o filho apresentar deficiência auditiva 57 (76%) mães opinaram negativamente. CONCLUSÕES: a grande maioria das mães entrevistada soube responder corretamente o que é a TAN e as informações por elas recebidas foram consideradas suficientes; houve predomínio de sentimentos positivos durante a realização do exame; a possibilidade de o filho apresentar deficiência auditiva foi considerada nula por três quartos das mães estudadas.

Hospital-based universal newborn hearing screening for early detection of permanent congenital hearing loss in Lagos, Nigeria

OBJECTIVE

To determine the feasibility and effectiveness of hospital-based universal newborn hearing screening programme for the early detection of permanent congenital or early-onset hearing loss (PCEHL) in Lagos, Nigeria.

METHODS

A cross-sectional pilot study based on a two-stage universal newborn hearing screening by non-specialist health workers using transient evoked otoacoustic emissions (TEOAE) and automated auditory brainstem-response (AABR) in an inner-city maternity hospital over a consecutive period of 40 weeks. The main outcome measures were the practicality of screening by non-specialist staff with minimal training, functionality of screening instruments in an inner-city environment, screening coverage, referral rate, return rate for diagnosis, yield of PCEHL and average age of PCEHL confirmation.

RESULTS

Universal hearing screening of newborns by non-specialist staff without prior audiological experience is feasible in an inner-city environment in Lagos after a training period of two-weeks. Notwithstanding excessive ambient noise within and outside the wards, it was possible to identify a test site for TEOAE screening within the hospital. The screening coverage was 98.7% (1330/1347) of all eligible newborns and the mean age of screening was 2.6 days. Forty-four babies out of the 1274 who completed the two-stage screening were referred yielding a referral rate of 3.5%. Only 16% (7/44) of babies scheduled for diagnostic evaluation returned and all were confirmed with hearing loss resulting in an incidence of 5.5 (7/1274) per 1000 live births or a programme yield of 5.3 (7/1330) per 1000. Six infants had bilateral hearing loss and the degree was severe (> or =70 dB nHL) in three infants, moderate (40 dB nHL) in one infant and mild (<40 dB nHL) in two infants. The age at diagnosis ranged from 46 days to 360 days and only two infants were diagnosed within 90 days.

CONCLUSIONS

Hospital-based universal hearing screening of newborns before discharge is feasible in Nigeria. Non-specialist staff are valuable in achieving a satisfactory referral rate with a two-stage screening protocol. However, a more efficient tracking and follow-up system is needed to improve the return rate for diagnosis and age of confirmation of hearing loss.

Neonatal hearing screening: a combined click evoked and tone burst otoacoustic emission approach

OBJECTIVE

This study evaluated an alternative transient evoked otoacoustic emissions method for screening hearing in newborn babies that may reduce the referral rate of initial screening.

METHODS

A total of 1,033 neonates (2,066 ears) from two hospitals were recruited. Subjects had their hearing screened in both ears using a combined approach-both click evoked OAEs (CEOAEs) and 1kHz tone burst evoked OAEs (TBOAEs).

RESULTS

1kHz TBOAEs were more robust than CEOAEs in terms of emission response level and signal-to-noise ratio (SNR) at both 1 and 1.5kHz frequency bands. The prevalence rate for CEOAE and TBOAE responses in these two frequency bands was significantly different. The combined protocol significantly reduced the referral rate-by almost 2 percentage points for first time screening.

CONCLUSIONS

The implementation of a combined 1kHz TBOAE/CEOAE screening protocol is a feasible and effective way to reduce referral rates, and hence false positive rates, in neonatal hearing screening programs.