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Neonatal Hearing Screening- Universal vs High Risk Screening- Experience in HK. Dr. Barbara CC Lam Consultant Honorary Clinical Associate Professor Department of Paediatrics and Adolescent Medicine Queen Mary Hospital 8 October 2005. Introduction.
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Neonatal Hearing Screening- Universal vs High Risk Screening- Experience in HK Dr. Barbara CC Lam Consultant Honorary Clinical Associate Professor Department of Paediatrics and Adolescent Medicine Queen Mary Hospital 8 October 2005
Introduction • Severe congenital hearing impairment (HI) is an important handicap affecting 1-3 per 1,000 live birth • The prevalence of moderate to profound hearing loss was 2 - 4 % of NICU infants • Infants with risk factors accounts for less than ~ 50% of cases • ~ 165 infants per year are born with significant HI in HK per year
Hearing is an important sensory input • Auditory stimulus perceives in the first few months of life forms the basis of speech, linguistics and cognitive development • The language ability, the social, emotional, comprehensive and motor development of HI are adversely affected
Early Intervention Improves Outcome • Yoshinaga-Itano showed age of the diagnosis of HI was the only significant variable to affect the language skill of HI child. • Several prospective studies showed thatthe prognosis for intellectual, language and speech development in the HI child can be improved significantly when the diagnosis is made early and intervention begins before 6 month of age • The first year of life, especially the first 6 months is most critical Robinshaw 1995 Apuzzo & Yoshinaga-Itano 1995 Moeller 1996 & Yoshinaga-Itano 1998
Past Situation in Hong Kong • Since 1978, Maternal and Child Health Centre (MCHC) provide ‘universal’ hearing screening using Behavioural Distraction Test for infants around 6-9 months • Most HA birthing hospitals perform hearing test (BAEP) for high risk infants • The usual age at diagnosis of hearing impairment especially for those without risk factors is usually at 2 year and most infants receive treatment and education after 2 years
Recent Change in Hong Kong • Most realized the importance of early diagnosis and early intervention • Some HA birthing hospitals pilot UNHS • Maternal and Child Health Centre (MCHC) replace the distraction test by Infant Hearing screening ( AOAE) for babies registered before 2 months through the early infant hearing & surveillance programme since Aug 2003 • There is a lack of a coordinated territory wide policy on hearing screening and the lack of territory wide registry with tracking and monitoring system
What is the most appropriate and cost effective newborn hearing screening programme for Hong Kong ?
Newborn Hearing Screening Strategies • High risk screening • Universal screening
High Risk Indicators America Academy of Paediatrics Joint Committee on Infants Hearing 1990 • Family history of HI • Congenital infection • Craniofacial anomalies • Low Birth weight (1500 grams or less) • Severe neonatal jaundice
High Risk Indicators • Ototoxic medications in toxic range • Bacterial meningitis • Severe depression at birth • Mechanical ventilation for or > 5 days • Syndrome known to include sensorineural and/or conductive hearing loss
High Risk Screening • ~ 5 - 10% of all babies born will exhibit one or more of these indicators • 2.5 - 10% of these infants confirmed to have permanent congenital hearing impairment (PCHI) • At least 50% of infants with PCHI do not have any of the risk factors
High Risk Multicentre Hearing Screening 1 year Project in HK 1999-2000 • Multicentre project involving 5 HA hospitals • Two stage distortion products OAE • Conventional auditory brainstem response for failed screening and babies with neurological abnormalities Chan KY et al (Sponsored by The Save Children Fund(HK)
High Risk Infants Family history, asphyxia, meningitis, NNJ, congenital infection, PPHN etc OAE (14-28 days) N Abn Abn Repeat OAE (<2 wks) ABR N Abn N MCHC Distraction test at 6-9 months ENT & Audiologist Abn ED for intervention Protocol of High Risk Infant Screening Project
Live Birth 19,922 Risk Factor 546 ( 2.7%) Default 13 (2.4%) OAE 533 ( 97%) CNS risk Additional ABR 210 ( 39%) 2nd OAE 70 failed Pass OAE but failed ABR - 13 ABR 46 ( 8.6%) ENT 13 ENT 30 * Hearing Loss 2 ( 0.3 %) *Hearing Loss 22 ( 4%) Summary of High Risk Infant Screening Result Default 54 failed
Multicentre High Risk Infants Hearing Screening Project • 1.2 per thousand (24 out of 19,922 LB) have HI - high risk approach detect less than 50% of cases • 2.4% of at risk infants have moderate to profound HI • HI infants were identified before age 4-6 months and all of them had received appropriate intervention before age of 9 months
Multicentre High Risk Infants Hearing Screening Project • OAE may miss some case with CNS defects • No significant HI was detected at age 9 months in those infants who passed newborn screening • Default rate for OAE is 2.4%, for ABR for those with CNS risk factors is 26% - screening best to be performed before hospital discharge & coupled with a robust tracking system
Criteria for Public Health Universal Screening:- • Easy-to-use screen tests - high sensitivity to minimize unnecessary referrals • The condition being screened for is not otherwise detectable by clinical means 3. Interventions are available to correct the condition once detected 4. Early screening, detection, and intervention result in improved outcomes 5. The screening program is documented to be in an acceptable cost-effective range
Universal Newborn Hearing Screening • Congenital Hearing Loss fulfills the established Criteria for Universal Screening • A universal newborn hearing screening with a coverage rate of more than 95% is a more vigorous approach to achieve the aim of identifying most, if not all babies with congenital hearing loss at an early age to enable timely habilitation
Universal Newborn Hearing Screening • Hospital based vs Community based? • Which screening tools ? • AABR ? OAE ? OAE and AABR
UNHS Projects in Hong Kong I. First Pilot hospital based UNHS - 2 stage OAE ( TYH)- 1999 II. Multicentre hospital based UNHS - Comparing different screening devices and protocols - 2001 • Pilot study of Community based UNHS by 2 stage OAE in 4 MCHC -2001 • Regional UNHS -2 stage AABR and cost effectiveness study – 2003-2005
Pilot UNHS- 2 stage OAE in TYH OAE Screen OAE Screen OAE Screen Day 1-4 Day 5-14 Day 21-30 Infants 806 913 872 Screened Failure 59% 21% 3.9% Rate PK Ng, Y Hui, BCC Lam et al HK Medical Journal 2004
Pilot UNHS- 2 stage OAE in TYH • Bilateral hearing loss is 0.28 • High parental acceptance of UNHS – Coverage rate is 99.3% • Unacceptably high false positive rate ( 20%) in first 2 week due to ear debris • Refer rate for diagnostic audiological test is 3.5% PK Ng, Y Hui, BCC Lam et al HK Medical Journal 2004
Questionnaires study on Parental Acceptance of Newborn Hearing Screening • 91% consider newborn hearing screening desirable • 82% favor pre-discharge screening • 56% do not have a sound knowledge on hearing developmental milestone, undesirable to rely on parental self surveillance to detect HI in their babies PK Ng, Y Hui, BCC Lam et al HK Medical Journal 2004
Hospital based Multi-centre UNHS – Screening Device and Protocol • 3 different screening protocols • 2-stage AABR (Algo model 2e Color Newborn Screener) • 2-stage AABR (Biologic 2 in 1 screener) • 2 stage OAE-AABR (Biologic 2 in 1 screener) • Pre-discharge screening
Hospital based UNHS- Comparisons for 3 Different Screening ProtocolsBWY Young, BCC Lam CM Wong et al 2002 AABR- OAE- ABear- AABR(Algo) ABear ABear( Bio) Failed first Test 5.3% 29.1% 15.1% Final Refer Rate 0.6% 5.0% 3.8% Average Screening 11 11 17.5 Time (min.) Disturbance score 1.21.7 0 0.7 1.5 1.8
Hospital-based Multicentre UNHSBWY Young, BCC Lam CM Wong et al 2002 • High coverage rate of 95% - UNHS is feasible before discharge from birthing hospital • The 2 stage AABR screening yielded the lowest refer rate - 0.6% • The time spent in the 3 screening methods are comparable • OAE screening cause the least disturbance to the babies, followed by AABR
Pilot Study of Community Based UNHS in MCHCKY Chan, SSL leung HKJ Paedatr 2004 • 4 MCHC in August 2000 to July 2001 • Infants with first MCH attendance at 2 weeks to 2 months • 2 Stage OAE, re-screened 2 weeks later if failed the first screening
Pilot Study of Community based UNHS in MCH • Uptake rate 77% of attendees at MCH • Overall coverage rate not known • Failure rate: 2nd screen 3.8% • Out of 3,949 screened, 4 cases of Bilateral HI - 1 per 1000 babies • Mean age of HI identification 85 days (vs 9-12 month for distraction test) KY Chan, SSL leung HKJ Paedatr 2004
QMH & PYNEH Universal Newborn Hearing Screening A regional 2-stage AABR and cost effective analysis
All babies born in QMH & PYNEH Stable and >35 weeks No Yes Distribute information sheet when baby is stable and >35 weeks Distribute information sheet on the first day of life 1st AABR same / next day after newborn examination 1st AABR screening Fail Fail Pass Pass 2nd AABR Screening on the same / next day Pass Discharge and encourage to attend MCHC for on going surveillance Fail UNHS Screening Protocol - 2-stage AABR – AABR
Counseling by Paediatrician Refer to audiologist for diagnostic BAER Paediatric follow-up appointment 4 weeks later Diagnostic BAER Follow-up once by paediatrician Follow-up by paediatrician Follow-up by ENT Surgeon Refer to Special Education Unit for early habilitation UNHS Screening protocol - 2-stage AABR – AABR Pass Fail
UNHS- QMH & PYNEH 2 stage AABR- 2003-2005 Total birth 14,604 Babies screened 14,560 Coverage rate 99.7% Failed 2nd screen 1.5% Confirmed HI 76 (0.5%) Bilateral HI 36 Unilateral HI 40
UNHS- QMH & PYNEH 2 stage AABR- 2003-2005 Time Median 1st screening 22 hrs 2nd screening 41 hrs Diagnostic BAER 43 days ENT 66 days Special ed. 158 days Hearing aid 198 days
Recommended Parameters for Effective UNHS Parameters Study AAP High Coverage Rate 99.7% 95% Good Sensitivity (RR) 1.5% 4% Zero false negative Bilateral HL 35dB Before discharge
Cost No. Per baby Cost Average cost/birth $ Equipment 2 109,161 18 Staff hours 5,098 20 min. 130-105/hr 40 Consumable 3,028 0.25 75 12 Total 70
UNHS: Cost Analysis • Capital cost of equipment • Manpower & consumable cost • Cost for confirmatory test • Life long quality of life • Differences in life-time learning capabilities • Education cost
Cost Effectiveness • Long term cost analysis showed that the cost of UNHS could be offset by savings from reduced burden on special education • Positive gain at 10-11 years after implementation.
Hospital vs Community Based - Coverage Rate Hospital based: TYH 2 stage OAE 98.9% LB QMH PYNEH 2 stage AABR 99.7% MCH based: Distraction test 60% at 9M 2 Stage OAE 72% of all attendees
Hospital vs Community Based High Sensitivity • Recommended parameter - Refer rate for diagnostic test Target < 4% • Refer rate for diagnostic test • Hospital based AABR program 1.5% • MCH based OAE program 3.8%
Hospital vs Community Based - Early Referral • Recommended Parameter - Target 100% before 3 months or shortly after birth • Mean age of referral for diagnostic test • Hospital based AABR program - 41hours • MCHC based OAE program - 54 days
Hospital vs Community Based - Parental Acceptance • Screening test is completed before discharge • Child back to China • High parental satisfaction • Less anxiety due to lower and earlier referral for diagnostic test
Hospital VS Community Based Cost Analysis Hospital based AABR MCH based OAE 8 centres ($M) 44 centres ($M) Capital cost 1.2 3.2 of equipment Annual labour cost 2.38 2.83 Annual consumables 2.5 0.8 Cost of diagnostic test 0.5 12 Cost per deaf child 0.33 0.95 identified
Available Supporting Facilities! • Hospital based UNHS • Available specialist support and expertise including audiologist, paediatrician and ENT surgeon for counseling and further audiological evaluation
Universal Hospital Based Predischarge Newborn Hearing should be Introduced • Efficacy of a screening program • Maximal coverage • Good sensitivity (low refer rate) • High specificity (low false negative rate) • High patient acceptance • Cost effective
The Way Forward - Collaborative model Combine the specific competencies of the 2 involved parties
Role of Community Centre • Establish and maintain a central registry and monitoring system • Establish and maintain a tracking program that monitor all referrals and miss • To provide mop up service for out-of-hospital births • Ongoing surveillance for late onset hearing impairments