“Standards for NHS Equipment”aka

“What Are We Measuring in NHS Programs?”

Barbara L. Kurman, Au.D., FAAAVice-President,

Northeastern Technologies Group, Inc., NYManaging Member,

Midlantic Technologies Group, LLC., PA

Judy Gravel, Ph.D.Director, Center for Childhood Communication

The Children’s Hospital of Philadelphia, PA

Faculty Disclosure Information

As a Special Instrument Distributor (SID), Barbara Kurman has contractual relationships with

most manufacturers whose products will be referred to in this presentation.

In the past 12 months, Judith Gravel has not had a significant financial interest or other

relationship with the manufacturer(s) of the product(s) or provider(s) of the service(s) that will be

discussed in this presentation.

This presentation will not include discussion of pharmaceuticals or devices that have not been

approved by the FDA. There will be no discussion or unapproved or "off-label" uses of pharmaceuticals or

devices.

Agenda

• Background: review of newborn hearing screening programs – who are we missing?

• Technologies and current devices – what is commercially available?

• Should We Have Standards for NHS?

• Other NHS product considerations

NIH 1993Consensus Conference

“The preferred model for screening should begin with an evoked

otoacoustic emissions test and should be followed by an auditory

brainstem response test for all infants who fail the evoked

otoacoustic emissions test.”

What hearing losses are we missing with newborn screening?

• The best screening tests are not 100% accurate

• Evidence suggests that at best, our screening tests are identifying about 80% - 90% of infants who have hearing loss in the newborn period (e.g., Norton et al., 2000; Davis et al., 1997; Lutman et al., 1997)

What hearing losses are we missing with newborn screening?

• Mild hearing loss < 30 - 40 dB HL• Some unusual configurations of hearing loss

– Isolated low-frequency hearing loss (both OAE and ABR technologies)

– Oddly-shaped hearing loss• Steeply sloping high-frequency hearing loss • Mid-frequency hearing loss

• Delayed onset and progressive hearing losses• AN and genetic IHC loss where OHCs are intact

(if only use OAE screening technology)

What hearing losses are we missing with newborn screening?

• Missing ‘deaf’ ears– Estimates of false-negative (false pass) rate:

• 1-2% of ‘deaf’ ears will pass ABR screening (Roger Marsh, CHOP 2006

• Repeated screening of a ‘failed’ ear to achieve a ‘pass’ will increase the likelihood of a pass response in a ‘deaf’ ear

Centers for Disease Control and Prevention (CDC)

Request for Proposals - January 2000

“Concerns have been raised about infants who fail OAE but pass ABR and are then dismissed from follow-up. These infants may have a mild

loss that was missed by ABR”

“A Multi-Center Evaluation of How Many Infants with Permanent Hearing Loss

Pass a Two-Stage OAE/A-ABR Newborn Hearing Screening Protocol”

Johnson, White, Widen, Gravel, James, Kennalley, Maxon, Spivak, Sullivan-Mahoney,

Vohr, Weirather, and Holstrum

Pediatrics 116(3) Sept 2005; 663-672

• Prospective, cohort study

• 7 geographically-dispersed birthing centers in U.S.

• Ethnic & socio-economic characteristics representative of U.S. population

Johnson et al. (Pediatrics 2005 )

• 2-technology screening protocol:– TEOAE (Otodynamics) or DPOAE

(Biologic)– A-ABR (ALGO: 35 dB nHL click)

• Some used protocol in both well-baby and NICU

Johnson et al. 2005

86,634 infants: screened in 7 Centers• 704 (0.8%) failed OAE/failed A-ABR

screening– Comparison Group: 604 (85.8%) returned for

diagnostic tests• 3, 362 (4%) failed OAE/passed A-ABR in

at least one ear– Study Group: 1,524 (44%) infants were

enrolled for follow-up

Johnson et al. 2005

Study Group• 973 infants (64%) returned for audiologic

follow-up• Audiologic tests completed at mean age

9.7 months– VRA (AC & BC); – tympanometry; – OAE

Johnson et al. 2005

Johnson et al. 2005

21 infants (30 ears) who failed OAE & passed A-ABR in newborn period had permanent bilateral or unilateral HL at ~9 months of age

Degree (poorer ear) of PHL (VRA) in Study & Comparison Groups

(Johnson et al. 2005)

Mild

(25-40 dB)

Mod

(41-70 dB)

Sev/Prof

(>71 dB)

Total with PHL

Study Grp

15

(71.4%)

5

(23.8%)

1

(4.8%)

21

(100%)

Comp Grp

31

(19.6%)

64

(40.5%)

63

(39.9%)

158

(100%)

Total 46

(25.7%)

69

(38.5%)

64

(35.8%)

179

(100%)

Examples of PHL (VRA) in Infants who fail OAE/pass A-ABR

(Johnson et al. 2005)

ID # .5 kHz 1 kHz 2 kHz 4 kHz

091 20 25 35 35

055 25 25 20 30

053 25 25 30 35

130 25 30 35 45

002 25 25 30 25

Examples of PHL (VRA) in Infants who fail OAE/pass A-ABR

(Johnson et al. 2005)

ID # .5 kHz 1 kHz 2 kHz 4 kHz

131 30 35 40 45

005 45 40 40 60

122 40 40 45 40

072 50 40 30 40

003 45 45 60 55

Identifying Mild PHL in Infants: Challenges

Norton et al. (2000)

• Three measures (ABR, TEOAE, DPOAE) - able to identify majority of ears with moderate hearing loss or greater.– “more difficult for any tool to distinguish

between normal hearing and mild hearing loss” (p.533)

– “some ears with mild hearing loss will be missed, regardless of which test is used” (p.534)

Cone-Wesson et al. (2000); n = 2995 infants

• Ears with mild PHL (n=22 [30.2%] of 86 ears with PHL) confirmed at 8-12 months (VRA)

• Outcomes (neonatal ABR and OAE [DPOAE and TEOAE])– 10 ears failed both OAE and A-ABR tests, – 4 ears passed both OAE and A-ABR tests, – 4 passed ABR and failed both OAE measures– 2 failed ABR and passed OAE tests. – 2 ears that failed ABR passed DPOAE but

failed TEOAE.

Identifying Mild PHL in Infants: Challenges

Issues Impacting NHS Data

• No ANSI standards for use in calibration of OAE or ABR devices

• Variability among screening devices test parameters

• Individual variability of SPL at TM – issue most significant for ABR

MuffFlat plate

Ear coupler baseMicrophone B&K type 4144

Method of measuring stimulus output of AABR muffs

From: John Stevens 2004

Variability

“Based on the estimate of the RETSPL value, the results indicate that the stimulus levels in current equipment [automated ABR] are considerably above the stated stimulus level of 35 dB HL.”

Estimated: 38.5 to 44.9 dB HL

Stevens 2004

Eight Manufacturers of Hearing Screening Devices Commercially Available in U.S.

• Bio-logic• GN Otometrics –

Madsen• GSI – Grason

Stadler: VIASYS• Otodynamics, Ltd

• Maico Diagnostics

• Natus• Interacoustics

USA• Intelligent Hearing

Systems• SonaMed Corp

Devices: Types available currently:

• TEOAE only (1 manufacturer only)• DPOAE only (1 manufacturer only)• TEOAE and/or DPOAE (5

manufacturers)• Screening OAE and/or screening ABR

in one device (6 manufacturers)• Screening ABR only (5 manufacturers

offer ABR as stand-alone device)

Commercially-Available Screening Products

• Single technology: – TEOAE, DPOAE, ABR

• Combined technologies – can be configured in multiple ways– TEOAE, DPOAE, ABR

What the Products Have in Common

• Designed for ease of use - automation• Parameters cannot be changed by screening

personnel• All provide only “pass” or “refer” outcome• Probe tips or couplers (circumaural cushions)

are disposable (“single use”)• All identify some violation of proper test

conditions: “low stimulus level”, “too noisy”.

TEOAE: Examples Product Variability

Manuf Stimulus Stim Level

(dB SPL)

Pass Criteria

1 6 freq bands:

1.5 – 4 kHz83 4 dB S/N

2 Primary resp. band: 1.6 – 3.2

kHz

84 6 dB S/N

3 Primary resp. band:

1.2 – 3.5 kHz

80 6 dB S/N

DPOAE: Examples Product Variability

Manuf Stimulus

f1-f2

Levels

L1- L2Pass Criteria

1 4 tonal pairs

(f1-f2)

(2 – 5 kHz)

65/55 6 dB SNR in 3 frequencies = pass (not

consecutive)

2 5 tonal pairs: 2-6 kHz

65/55 3 out of 5 frequencies = pass which meet: Min

-5 dB SPL amplitude & min 8 dB SNR, or min

noise floor amplitude -17 dB SPL

Automated ABR: Examples Product Variability

Manuf Change levels?

Ear Canal Calibration?

Transducer Choice?

1 yes yes yes

2 yes yes No –

probe only

3 yes** ? No –circumaural

only

Calibration• Manufacture Recommends:

– Some recommend a yearly calibration: (e.g., on site by a NASED –certified audiometric technician or ship device back to factory)

– Some recommend no annual calibration is needed

• NASED (National Association of Special Equipment Distributors) – examining calibration standards for OAE devices where no current national standards exist

Lack of National Standards for NHS

Problems Associated with the Lack of National Standards for

NHS Programs

• Prevalence data may not be comparable across programs– Impacts our understanding of differences in

prevalence among populations and geographic regions

– Impacts public health, education, fiscal policy planning

Comparing Within & Among NHS Data Sets

• NYS Demonstration Project – same protocol and pass/fail criteria

• English Screening program – same protocol and pass/fail criteria

• Ontario screening program – same protocol and pass/fail criteria

• U.S. screening program - variability of screening protocols & pass/fail criteria among hospitals & states and across the nation

Problems Associated with the Lack of National Standards for

NHS Programs

• Manufacturer algorithms designed to provide best performance (low fail rates) along with high sensitivity (most hearing losses identified)

• Pass-fail criteria differ among devices• Few data from manufacturers on the

statistical false-negative (false-pass) rate

Screening outcome by ABR compared to Four Different DPOAE Pass Criteria

(Barker, Lesperance & Kileny, 2000)

• 1184 ears examined: all ears passed ABR screening (35 dB nHL)

• DPOAE screening

• Depending on four different pass-refer criterion applied, between 64% and 89% of ears passed screening

Solutions: Refer to accepted Position Statements

and Guidelinesor

State Regulations and Guidelines

Newborn Hearing Screening• Objective measure must be used

– Auditory Brainstem Response (ABR)– Otoacoustic Emissions (OAE)– pass-refer criteria preferred– automated response detection preferred– non-professional: pass-refer outcome

required

JCIH 2000

JCIH 2000

• In-hospital screening– variety of protocols useful– one technology and two technology protocols

• Well-baby nursery (WBN) versus Neonatal Intensive Care Unit (NICU)

• Re-screen (out-patient)– within 1 month of discharge– minimizes number of referrals audiologic

assessment: reduces over-referral rate (false-positive outcomes)

• Physiologic screen of hearing only• Screening Equipment (OAE – ABR)

• not specified• required to be fully automated (only

providing pass-refer outcome) when used by technical personnel

The Law:

NY State UNHS Regulations

Solutions: Use published parameters from clinical

trials that provided data about accuracy of screening tests (sensitivity & specificity)

Only one study available:

Norton et al. 2000

NIH-NIDCD

Multi-center Investigation Sponsored by NIH-NIDCD

Investigators: Norton, Gorga, Widen, Folsom, Sininger, Cone-Wesson, Vohr et al., 2000

“To determine the accuracy of three measures of peripheral auditory system status (TEOAE, DPOAE and ABR) applied in the perinatal period for predicting behavioral hearing status at 8-12 months corrected age.”

NIH Multi-Center Study(Norton et al. Ear & Hearing: 5; 2000)

• 7 institutions• 7,179 infants evaluated

– 2,348 = WBN babies– 4,478 = NICU babies– 355 = well babies with high risk

indicators

• Targeted for VRA @ 8-12 months : NICU, WBN with HRI, and 80 WBN (no HRI) infants who failed one or more neonatal testing

• 3,134 (64%) returned for VRA

Screening Test Accuracy for detecting HL > 30 dB HL

using VRA MRL, SAT and PTA2 (2 + 4 kHz) and PTA3 (1, 2, 4 kHz) at 8-12mos as ‘gold standard’

Progressive HL and ME pathology excluded (Norton et al., 2000)

MRL @ 1 kHz

MRL @ 2 kHz

MRL @ 4 kHz

SAT PTA2 PTA3

DP 75/75

0.75 0.89 0.81 0.87 0.86 0.84

DP 65/50

0.70 0.92 0.89 0.92 0.88 0.83

TEOAE @ 80

0.74 0.92 0.88 0.94 0.90 0.84

ABR @ 30

0.90 0.89 0.82 0.91 0.88 0.87

Conclusions: Screening Tests (Norton et al., 2000)

• Screening test failure rate increased as degree of hearing loss increased

• DP 65/50, TEOAE and ABR similar in identifying HL of moderate degree and greater (PTA2: 2.0 + 4.0 kHz)

• Overall poorer performance of DPOAE 75/75 condition

Could We Do It With Current Commercially Available Devices?

Automated ABR Test ParametersNorton et al. 2000

• Custom-designed system; not available commercially

• 30 dB nHL clicks– Automated Pass Criterion: Fsp > 3.1 – Visual confirmation of wave V (Observer

Based Criteria: OBC) in addition• Stimuli calibrated using OAE system &

probe– Tester could adjust level with resultant voltage

setting for click– Click transduced via OAE probe

Commercially-Available Automated ABR Screening Products

• 5 of 6 manufacturers allow probe/ear canal transducer option– Verify level within tolerance parameters in

order to run the test

• 2 of 6 manufacturers allow either probe/ear canal transducer or circumaural cushion option– Verify level within tolerance parameters in

order to run the test

Commercially-Available Automated ABR Screening Products

• 1 manufacturer uses circumaural cushion only– ? Verify level

• 6 of 6 manufactures allow user (administrator) to set stimulus level

• 3 manufacturers employ some version of Fsp stopping criteria to determine pass/fail

• 3 manufacturers can meet Norton et al. 2000

Distortion Product OAE Test ParametersNorton et al. 2000

• Commercially available product (not screening device)

• Evoking stimuli: 65/50 dB SPL– Stimulus level (SPL) measured in ear canal

prior to test

• Pass criteria: 3 dB S/N +2 SD (equivalent to 8-10 dB S/N) at 2, 3, & 4 kHz (f2)

Commercially-Available DPOAE Screening Products

• 6 of 9 manufactures allow either the user or administrator to set stimulus levels and/or pass-fail criteria

• 3 manufacturers ship to purchaser without a way to change levels or pass-fail criteria

• 6 manufacturers can meet Norton et al. 2000 criteria

Transient OAE Test ParametersNorton et al. 2000

• Commercially available product (not screening device)

• Evoking stimulus: 80 dB pSPL click– Stimulus level (SPL) measured in ear canal

prior to test

• Pass criteria: S/N = 3 dB at 1.5 kHz; 6 dB at 2, 3, & 4 kHz bandwidths

Commercially-Available TEOAE Screening Products

• 5 manufactures have available screening products

• Products cannot be changed re: stimulus level or pass/fail criteria

• 5 manufacturers can meet Norton et al. 2000 criteria

Lacking A National or Agreed-Upon Standard –

What Else Should You Look for in Selecting Screening Devices?

Considerations for Product Purchase• Stand alone device: 1 technology

– With true database management– Without true database managment

• Combination device: OAE/ABR – With database management– Without database management

• Ease of use• Cost of instrument & disposables• Flexibility• Durability• Maintenance • Service, support & training

Suggestions for How Screening Programs Can select an Appropriate Device

• Decide what you want to screen for (sensory, neural, mild HL, etc.)

• Consider the screening environment and screening personnel

• Require manufacturers specifications to reflect all stimulus parameters and pass/fail criteria

• Have a evidence-base for selection of screening parameters and pass/fail criteria

Your Questions and Comments