1. Evaluation of pure tone audiometry
and impedance screening in infant
school children
2013/2014
Omar haj Okod (10110073)
Abdulwaris Khan (11110031)
Mohammed Sulaiman (10110060)
Hamad Emad Thuhayr (10110067)
Jihad Al-Shabaan (11110014)
Sameer Mamoon Haj Omar (9110024)
Multi CAT (diagnosis)

2. Abstract of the study
 Objective:
1.
2.
To evaluate impedance measurements VS. pure tone audiometry as a screening program for the
detection of middle ear changes associated with hearing loss in infant school children.
To estimate the costs to the health authority of each method.
 Design:
Two stages were involved:
o Pure tone audiometry carried out by nurses.
o Impedance screening by physicians.
 Setting:
18 infant or primary schools in Langbaurgh, Cleveland, UK.
 Participants:
610 previously unscreened infant school children took part in the study.

3. Abstract of the study
 Measurements and main results:
1.
2.
3.
The sensitivity and the predictive value of a positive test in two stage
impedance screening was markedly superior to that of pure tone
audiometry.
The specificity was similar using the two methods.
the impedance method was more rapid and estimated to consume less
resource as a screening procedure than pure tone audiometry.
 Conclusion:
The superiority of the use of impedance screening established in this
study should be confirmed in a subsequent audit carried out purely by
school nurses.

6. STEP 1: Are the results of
the study valid?

7. Q1: Was the diagnostic test evaluated in a
representative spectrum of patients?
• Six year old schoolchildren in 18 infant schools in Langbaurgh,
Cleveland, UK were the potential entrants to the study.
• Children already known by the school nursing service to have
middle ear disorders were excluded from further study.
• The answer is YES!!!

8. Q2: Was the reference standard applied
regardless of the index test result?
• The reference standard for diagnosing hearing loss is pure tone
audiometry which was applied for all infant school children.
• Impedance measurements is an alternative method in which it does
not lead the diagnosing of hearing loss directly but it measures the
resistance to sound by the middle ear and its contents. However,
disorders of the middle ear may lead to established hearing loss. It
was also performed in all samples.

9. Q3: Was there an independent, blind comparison between the
index test and an appropriate reference “gold standard” of
diagnosis?
• The results of the alternative method were not known to the
respective operators.
• Impedance were conducted by physicians in relevant schools.
• Pure tone audiometry were conducted by 9 school nurses in all 18
schools chosen.

10. STEP 2: What were the
results?

11. Q1: Are test characteristics presented?
• This table illustrates the number of identified cases in either the
two methods or one method and the number of unidentified
cases. This table contains the numbers of the first stage.

12.  This table illustrate the number of infants
who were screened by Pure Tone
Audiometry (PTA) measurements.
 This table illustrate the number of infants
who were screened by Impedance
measurements.

13.  This table illustrate the sensitivity,
specificity and positive predictive value of
PTA and Impedance tests.
 This table illustrate the costs of the two tests
PTA and Impedance.

14. STEP 3: Applicability of the
results.

15. Q: Were the methods for performing the
test described in sufficient detail to permit
replication?
•
•
Yes. It was described in the first 5 slides.
The screening test that was recommended by the authors is the Impedance
measurements. The reasons they stated are:
o
o
o
Only three Impedance tympanometers would be required for the annual testing of hearing loss in infant
school children in the catchment area. PTA measurements require 14 audiometers.
It will cost less than PTA measurements.
It is more comfortable test than OTA because of:
• The ease of performing it.
• It requires less time compared with PTA measurement.
• The cooperation of the child will not be a problem during the test.