Prevalence and referral rates in neonatal hearing screening program using two step hearing screening protocol in Chennai – A prospective study

https://doi.org/10.1016/j.ijporl.2015.07.043Get rights and content

Abstract

Objective

To estimate the prevalence and referral rates in well born and high risk babies using two step hearing screening protocol with Distortion Product Otoacoustic Emissions (DPOAE) and Automated Auditory Brainstem Response (AABR).

Method

A prospective study was carried out on 1405 neonates (983 well born babies and 422 high risk babies) who were screened during May 2013 to January 2015 at Institute of Obstetrics and Gynecology, Madras Medical College, Chennai. All neonates were screened using two step screening protocol. They were initially tested with DPOAE. Referred babies in DPOAE were screened with AABR subsequently.

Results

Among 1405 (100%) neonates 983 (69.96%) were well born babies and 422 (30.03%) were high risk babies. Total referral rate in DPOAE was found to be 311 (22.13%) among which 195 (13.87%) were well born babies and 116 (8.25%) were high risk babies. Out of 311 babies 31 (2.20%) babies were referred in AABR screening. In 31 babies referred in AABR 11(0.78%) were from well born group and 20 (1.42%) were from the high risk group. Further diagnostic evaluation of these babies, 2 (0.14%) were confirmed to have hearing loss. This study reveals, the prevalence of congenital hearing loss in our population is 1.42 per 1000 babies.

Conclusion

Using two step protocol especially AABR along with DPOAE at the initial level of testing significantly reduces referral rates in new born screening programs. Also AABR decreases the false positive responses hence increasing the efficiency of screening program.

Introduction

Hearing Screening in developing countries with larger population is often challenging. New born hearing screening programs have been implemented over various institutions and hospitals across India [1]. Physiological tests like Evoked Otoacoustic emissions (EOAE) and Automated Auditory Brainstem Response (AABR) have been commonly used in new born hearing screening programs. Joint Committee for Infant Hearing (JCIH) positional statement in 2007 recommended both OAE and AABR to be included for high risk babies hearing screening protocol to identify neural hearing loss at initial level of screening [1].

There are several reports in literature that using double step screening protocols significantly reduces the referral rates in well born and high risk babies [2]. Using AABR in addition to EOAE decreases false negative and false positive referral rates significantly but incur higher cost [2], [3]. Use of AABR alone or EOAE alone causes low sensitivity and specificity in high risk babies to identify neural hearing loss [4], [5]. Also the prevalence of Auditory Neuropathy Spectrum disorder (ANSD) has been reported to be high in high risk babies [6].

In the Indian scenario, hearing disability is the second common disability after locomotor disability as per the National Sample Survey (2002) among rural and urban households [7]. Various programs namely National Programme for Prevention and Control of Deafness (NPPCD) in 2006 [8], and Rashtriya Bal Swasthya Karyakram (RBSK) in 2013 [9] initiated by the Government of India are aiming at early identification, early intervention and reducing the total disease burden of hearing impairment and deafness. Hearing screening programs in India are often conducted in medical college hospitals and speech & hearing centers [10]. Only 63% of speech and hearing centers have been reported to use EOAE and AABR in hearing screening programs [10].

According to World Health Organization (WHO) report on new born and infant hearing screening; current issues and guiding principles for action in November 2009, Members of the International Association of Logopedics (IALP) Audiology Committee have recently reported on new born hearing screening program during 2008. The report states that in India protocol used in 1st and 2nd stage of hearing screening are Transient Evoked Otoacoustic Emissions (TEOAE) alone and AABR are used in 3rd stage of hearing screening [11]. DPOAE and AABR are rarely used in Indian scenario as a two step hearing screening protocol (screening with EOAE and AABR). In this context we carried out a prospective study in our hearing screening program using DPOAE and AABR.

Section snippets

Methods and materials

1405 neonates (723 males and 682 females) were screened during May 2013 to January 2015 to estimate the prevalence and compare the referral rates in well born as well as in high risk babies at Institute of Obstetrics and Gynecology, Madras Medical College, Chennai – a government organization. Prior to the study ethical committee approval was obtained from the local ethical committee at Madras Medical College. All neonates screened in the present study were in the age range of 2–28 days with the

DPOAE referral rates

Among 1405 (100%) neonates 983 (69.96%) were well born babies and 422 (30.04%) were high risk babies. In the initial testing with DPAOE 1094 (77.86%) babies were found to have passed DPOAE screening bilaterally. Total referral rate in DPOAE was found to be 311 (22.14%). Among well born and high risk babies, 195 (19.84%) in well born babies and 116 (27.49%) in high risk babies were referred during DPOAE testing.

When unilateral and bilateral referral rates were considered in well born babies,

Discussion

The prevalence of congenital bilateral hearing loss in the present study is comparable to the previous studies in India [14], as well as other countries [12], [20]. Prevalence rate of congenital hearing loss is often reported to be from 1% or 2% [12], [13] to 4% or 6% [14], [15] per 1000 population. The estimated prevalence of hearing loss in the literature has been reported to be varying with the protocol used [2], [4], [5] degree of hearing loss, consideration of unilateral vs bilateral

Conclusion

Hearing loss is one of the major disabilities in India affecting speech and language development in children. Early identification of hearing loss and early intervention significantly improves speech and language development [21]. Two step hearing screening programs are rarely being carried out in India. The present study was carried out to analyze the prevalence and referral rates using two step hearing screening protocol. From the current study of neonatal hearing screening, we conclude that

References (24)

  • Directorate General of Health Services

    National Programme for Prevention and Control of Deafness, Project Proposal

    (2006)
  • Rastriya Bal Swasthya Karyakram (RBSK)

    Operational Guidelines

    (2013)

    • Cited by (18)

    View all citing articles on Scopus
    View full text
    Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.