Global burden of hearing loss
in the year 2000
Colin Mathers1, Andrew Smith 2, Marisol Concha3
1. Introduction
Hearing impairment is the most frequent sensory deficit in human populations, affecting more than
250 million people in the world. Consequences of hearing impairment include inability to interpret
speech sounds, often producing a reduced ability to communicate, delay in language acquisition,
economic and educational disadvantage, social isolation and stigmatisation. It may be worsened by
some medical conditions such as hypothyroidism, diabetes, and possibly hyperlipidemia, among
others.
Most congenital and childhood onset hearing loss is included as sequelae to various disease and
injury causes already included in the Global Burden of Disease Study. Examples include otitis media,
memingitis, rubella, congenital anomalies and non-syndromal inherited hearing loss. Adult-onset
hearing loss was not separately analysed in the original Global Burden of Disease for 1990 (1). The
leading causes of adult-onset hearing loss are presbycusis (age related hearing loss) followed by
noise-induced hearing loss. This paper reviews global data on hearing loss among children and
among adults, and estimates the global burden of adult-onset hearing loss. In addition, it provides
estimates of the prevalence of hearing loss among children and adults at various levels of severity.
In the Version 1 estimates for the Global Burden of Disease 2000 study, published in the World
Health Report 2001 (2), adult-onset hearing loss was the 2nd leading cause of YLDs at global level,
accounting for 4.6% of total global YLDs. This paper summarises the data and methods used to
produce the Version 3 estimates of adult-onset hearing loss burden for the year 2000, as published
in the World Health Report 2003.
2. Case and sequelae definitions
There is a diversity of definitions of hearing impairment, thus, comparison among studies is difficult.
We use WHO classification that classified hearing impairment according to the pure tone average in
the better hearing ear. Categories of hearing impairment ranges from “no impairment” to “profound
impairment” according the threshold level. The hearing threshold level, using audiometry, is to be
taken as the better ear average for four frequencies 0.5, 1, 2, and 4 kHz. (3) The different grades of
hearing impairment and their impact in performance are presented in Table 2.1. Duivestijn (4)
discusses the effect of different definitions on measured prevalence of hearing loss.
1 Epidemiology and Burden of Disease, WHO Geneva (GPE/EBD)
2 Prevention of Blindness and Deafness (MNC/PBD), WHO Geneva
3 Ministry of Health, Chile
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Global Burden of Disease 2000
Table 2.2 summarizes the GBD 2000 case and sequelae definitions for adult-onset hearing loss. For
the GBD 2000, the burden of adult-onset hearing loss has been estimated for moderate or greater
hearing impairment. While the prevalence of slight impairment (26-40dBHL) has also been
estimated, it has been assumed to have negligible disability weight and not to contribute to the YLD
for hearing loss.
Table 2.1 WHO grades of hearing impairment
Grade of Impairment
Audiometric ISO value
(average of 500, 1000, 2000,
4000 Hz)
0 (no impairment)
25 dBHL or less (better ear)
No or very slight hearing problems. Able to hear
whispers
1 (Slight impairment)
26-40 dBHL (better ear)
Able to hear and repeat words spoken in normal
voice at 1 metre
Impairment description
2 (Moderate impairment) 41-60 dBHL (better ear)
Able to hear and repeat words using raised
voice at 1 metre
3 (severe impairment)
61-80 dBHL (better ear)
Able to hear some words when shouted into
better ear
4 (Profound impairment
including deafness)
81 dBHL or greater (better ear) Unable to hear and understand even a shouted
voice
Source: (3)
Table 2.2 GBD 2000 case and severity-level definitions for adult-onset hearing loss
Cause category
GBD 2000 Code
ICD 9 codes
ICD 10 codes
Adult-onset hearing loss
U102
389
H90-H91
Severity level
Definition
Hearing loss, adult onset
Cases of adult onset hearing loss due to ageing or noise exposure. Excludes
hearing loss due to congenital causes, infectious diseases, other diseases or
injury.
Moderate hearing loss
Hearing threshold level in the better ear is 41-60 dBHTL (averaged over 0.5, 1,
2, 4kHz). (Not able to hear and repeat words spoken in normal voice at 1
metre). Person may or may not use a hearing aid
Severe hearing loss
Hearing threshold level in the better ear is 61-80 dBHTL (averaged over 0.5, 1,
2, 4kHz). (Not able to hear and repeat words using raised voice at 1 metre).
Person may or may not use a hearing aid
Profound hearing loss
Hearing threshold level in the better ear is 81 dBHTL or more (averaged over
0.5, 1, 2, 4kHz). (Not able to hear words when shouted into better ear). Person
may or may not use a hearing aid
3. Population prevalence and incidence studies
In spite of the number of published studies about hearing impairment (HI), the currently available
data is mostly incomplete and use different criteria, which causes difficulties in comparison and
estimation of the problem. Also, only relatively few studies have been carried out to date in
representative population samples. Table 3.1 shows the prevalence of hearing impairment measured
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Global Burden of Disease 2000
by pure tone audiometry in countries with available information. Population-based surveys conducted
in several developing countries have used the protocols developed by WHO to identify causes of HI
and prevalence.
Available data on hearing loss prevalence in children are summarized in Table 3.2.
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Global Burden of Disease 2000
Table 3.1. Prevalence studies for hearing impairment: adults
Country
Study
population
UK
Four cities
Italy
Milan, Padua,
Florence, Bari,
Palermo
Denmark
Denmark
Ref.
Sample
Prevalences
size
Age range available by
Years
Definition used
1980-86
25+, 45+, 65+ dBHL in
better ear
2,910
17-80
Age, sex
(7)
1989
25+, 45+, 65+, 90+ dBHL
in the better ear
2,170
18+
Age
Copenhagen males
(8)
1976
25+dBHL in better ear
0.5,1,2,4)
300
49-69
Age
Jutland (rural)
(9)
Early
1990s
25+ dBHL
1,397
31-50
Age x sex
Age
(5,6)
35+ dBHL
45+ dBHL,
Finland
Northern
Ostrobothnia
(10)
1997
21+, 40+, 70+, 95+ dBHL
in the better ear
(0.5,1,2,4)
5,400
5-75
USA
Framingham
(11)
1979
25+ dBHL (0.5,1,2,4
kHz) in better ear
2,293
57-89
USA
Beaver Dam,
Wisconsin
(1214)
1993-95
26+, 41+, >60 in WORSE
ear (0.5,1,2,4 kHz )
3,753
48-92
Age x sex (26+
only)
>25 dBHL in better ear
(0.5,1,2,4)
USA
Beaver Dam,
Wisconsin
(1516)
1987-88
26+, 41+, >60 in WORSE
ear (0.5,1,2,4 kHz )
USA
NHANES 1
national
(1718)
1971-75
25+ dBHL in the better
ear (HFPTA scale 1,2,4
kHz)
2,506
55-74
Age x sex
USA
HHANES
Hispanic
Americans
(19)
1982-84
26+, 41+ in WORSE ear
(0.5,1,2 kHz )
2,751
20-74
Age x sex
Brazil
Residents of the
city of Canoas,
RS, Brazil
(20)
2003
26+,41+, 61+, 81+ dBHL
or, better ear
3,858
All ages
Age, sex
Australia
South Australia
(21)
1996?
25+, 35+, 45+, 65+ dBHL
in better ear
9,027
15+
Age x sex
11,402
All ages
Age
5,432
All ages
Age
48-92
0.5,1,2,4)
Oman
National
(22)
1996-97
26+, 41+ dBHL (1,2,3
kHz bilateral/better ear)
India
Vellore, Taluk,
Tamil Nadu
(2324)
1997-98
26+,41+, 61+, 81+ dBHL
or, better ear
India
Lucknow rural
(25)
1975-76
15+, 30+, 60+ dBHL,
bilateral deafness and
unilateral deafness
904
All ages
Age x sex (15+)
Age (30+,60+)
India
Lucknow urban
(26)
1970
15+, 30+, 60+ dBHL,
bilateral deafness and
unilateral deafness
904
All ages
Age x sex (15+)
Age (30+,60+)
Sri Lanka
Kandy district
(2324)
19982000?
27+, 41+, 61+ 81+ dBHL,
better ear (1,2,4 kHz
bilateral/better ear)
4,858
All ages
Age (41+ only)
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Global Burden of Disease 2000
Nepal
Two regions
(27)
1990?
31, 51+, 81+ dBHL,
better ear (1,2,4 kHz
bilateral/better ear)
15,845
5+ years
Age
China
Sichuan
(2829)
1986-87
27+, 56+, 91+ dBHL,
better ear
126,876
All ages
Age, sex
(27+ only)
Korea
Communitybased and
health clinics
(30)
1994-97
27+, 41+, 56+, 71+
dBHL, both ears;
presbycusis only
25+
Age x sex
Age (56, 71)
5
39,004
Global Burden of Disease 2000
Table 3.1 (continued). Prevalence studies for hearing impairment: adults
Thailand
17 provinces
(31)
1988-90
41 dBHL, better ear
7,499
All ages
Thailand
Bangkok + 5
provinces
(31)
1986-87
41+, 61+, 81+ dBHL,
better ear (0.5, 1, 2 kHz
bilateral/better ear)
1,797
All ages
Total only
Indonesia
Bandung
municipality &
district
(2324)
1997-98
26+, 41+, 61+ 81+ dBHL,
(1,2,4 kHz bilateral/better
ear)
5,604
All ages
Age (41+ only)
Myanmar
Yangon
(2324)
1997-98
26+, 41+, 61+ 81+ dBHL,
(1,2,4 kHz bilateral/better
ear)
5,604
All ages
Age (41+ only)
Vietnam
6 selected
provinces (3
north, 3 south)
(32)
26+, 41+, 61+ 81+ dBHL,
(1,2,4 kHz bilateral/better
ear)
13,120
6 months
and older
Age x sex
Nigeria
3 states: Akua
Ibom, Benue,
Katsina
(33)
26+, 41+, 61+ 81+ dBHL,
(1,2,4 kHz bilateral/better
ear)
8,975
All ages
Age (41+ only)
20002001
Standardized prevalence of adult-onset hearing loss
Prevalence studies use different thresholds (and in some cases different definitions in terms of
frequencies and better or worse ear) and different age groups. Where non-WHO thresholds used,
the prevalence of hearing impairment at the WHO thresholds was interpolated assuming the log of
the cumulative prevalence is linear with threshold. This relationship holds reasonably well in most
studies.
Where prevalences were not available by sex, the sex ratio from a similar study in the same region
was assumed. Prevalences were estimated for GBD age groups and the WHO hearing impairment
thresholds. Table 3.3 summarizes these estimates showing age-standardized prevalences for ages 15
and over.
Prevalence of adult onset hearing loss was estimated by subtracting from prevalences at ages 20 and
over, the estimated prevalence of hearing loss for teenage children (15-19 years) or the nearest
similar age group for which prevalences available. It is assumed that the incidence of adult-onset
hearing loss associated with otitis media and other infectious and non-infectious causes included
elsewhere in the GBD 2000 cause list is negligible compared to the incidence of adult-onset hearing
loss associated with age-related hearing degeneration or noise-induced loss. The estimated
prevalence of hearing loss for teenage children is summarized in Table 3.4.
Figures 3.1 and 3.2 summarize the estimated age-standardized prevalences of adult-onset hearing
loss at 41+ dBHTL and 61+ dBHTL respectively for the studies listed in Table 3.3. Figure 3.3
shows the range of male/female prevalence ratios for these studies.
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Global Burden of Disease 2000
Table 3.2 Prevalence studies for hearing impairment: children
Country
Study
population
Ref.
Years
Definition used
Sample
size
Prevalence
Age range
%
Childhood
0.05 – 0.23
Developed
Review
(34)
Review
41+ dBHL better ear
UK
Trent region
(35)
1985-1993
40+ dBHL better ear at
0.5, 1, 2, 4 kHz
552,558
0-9
0.133 birth
prevalence4
USA
Atlanta
(36)
1991-93
40+ dBHL better ear at
0.5, 1, 2 kHz
255,742
3-10
0.11
USA
NHANES II
and Hispanic
HANES
(37)
1982-1984
31+ dB HL better ear
7,888
6-19
African-Am.
Cuban Am.
Mexican Am.
White, non-H.
USA
NHANES III
(38)
Developing
Review
(34)
Review
41+ dBHL better ear
Thailand
Bangkok
schools
Rural schools
(31)
?
41+ dBHL better ear
Sierra Leone
Panguma
(39)
1992
Angola
Luanda
(40)
Zimbabwe
6-19
0.7 (16+)
0.4 (26+)
Childhood
0.2-0.42
10,242
2,153
School age
Children
3.9
6.1
26+, 41+, 61+ dBHL
better ear
2,015
5-15
1992?
31+ dBHL better ear at
.5, 1, 2 kHz
1,030
Schoolchildren
2.0
(41)
1970s
31+ dBHL better ear
885
Schoolchildren
3.3
1990?
31+ dBHL better ear at
2 & 4 kHz
5,368
Primary
school age
2.2
31+ dBHL either ear at
.5, 1, 2 kHz
854
Primary
school age
3.0
Kenya
Kiambu
district
(42)
Tanzania
Northern
inland district
(43)
1988-94
16+, 26+ dB HL at 0.5,
1, 2 kHz better ear
6,166
0.78
1.21
0.60
0.38
Severe/profound
South
Africa
Poor rural
district in
Western Cape
(44)
Swaziland
1st year
schoolchildren
(44)
Saudi
Arabia
Riyadh
(45)
2.58 (26-40)
0.65 (41-60)
0.50 (61+)
0.35
1990?
21+, 31+, 41+ dBHL
better ear
401
6-13
1997
20+dBHL, Air cond at
.25-.8kHz & .5-4kHz
bone cond, unilateral or
better ear bilateral
6421
2m – 12y
2.0 (31+)
0.5 (41+)
7.7
4 This figure refers to what the authors call “permanent childhood hearing impairment”– that is
sensorineural hearing loss and includes 16% who had post-natally acquired loss. The prevalence rate
for congenital hearing impairments was 0.112%. The figures are not directly comparable with data from
the WHO studies which include conductive loss.
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Global Burden of Disease 2000
Table 3.3. Estimated prevalences of adult onset hearing loss for adults aged 15 years and over
Age standardized prevalence (%)
Male/Females prevalence ratio
26+
41+
61+
81+
26+
41+
61+
81+
UK (1)
11.8
4.0
1.1
0.3
1.2
1.1
1.0
0.9
Italy (2)
12.7
4.4
1.3
1.3
1.2
1.1
1.0
1.0
Denmark (3)
12.8
3.5
0.8
0.1
1.9
2.3
1.5
0.8
7.4
2.3
0.5
0.2
1.4
1.5
1.1
0.9
Australia
11.8
2.6
0.4
0.1
1.9
2.4
1.3
0.7
USA NHANES1 (5)
11.5
3.4
0.8
0.1
1.7
1.6
1.0
0.5
8.7
2.5
0.6
0.1
2.2
1.6
1.0
0.5
10.0
3.0
0.7
0.1
2.1
1.6
1.0
0.5
China (1)
4.0
2.8
1.3
0.3
1.0
1.0
1.0
1.0
Korea (8)
15.5
2.8
0.3
0.2
1.3
1.5
1.1
1.0
7.6
4.4
2.5
0.8
1.1
1.0
1.0
8.0
1.5
0.1
1.0
1.0
1.0
9.8
6.2
3.1
1.5
1.1
1.2
1.0
1.0
Finland (4)
BeaverDam (6)
Hispanic (7)
India
Vellore (1)
Vellore 2 (1)
Lucknow Urban (9)
7.3
5.6
3.5
2.3
1.0
1.0
1.0
1.0
Nepal (10)
Lucknow Rural (9)
15.3
8.7
4.5
2.5
1.2
1.4
1.4
1.0
Oman (11)
11.2
6.2
3.0
1.5
1.1
1.1
Indonesia (1)
7.1
1.4
0.1
1.5
1.0
1.0
Myanmar (1)
8.6
2.7
0.0
1.2
1.0
1.0
10.0
3.4
0.5
1.3
1.0
1.0
11.6
2.9
0.9
1.3
1.1
1.1
SriLanka (1)
21.7
Thailand (12)
Nigeria (1)
4.5
1.3
1.1
Notes:
(1)
Overall sex ratio at each threshold assumed to apply for each age group.
(2)
Odds ratio for measured and self -reported hearing loss by sex 1.0; but around 2 for noise exposure which is greater in manual
occupations - so possibly a male excess. UK sex ratios used as proxy.
(3)
Prevalences for missing age groups estimated using Finnish and Australian age patterns.
(4)
Danish sex ratios used for age groups 30-50.
(5)
Prevalences extrapolated to all ages 15+ using UK age patterns and sex ratio of 1.56. Prevalence ratio of 26+/41+ assumed to be the
same as in the Beaver Dam study.
(6)
Prevalences extrapolated to all ages 15+ using Australian age patterns.
(7)
Prevalence estimates based on sample-weighted average of prevalences for Mexican and Cuban born Americans. Prevalence of hearing
impairment in better ear estimated using ratio for better ear to worse ear from Beaver Dam study. Prevalence adjusted for exclus ion of
4kHz frequency using data from the Framingham study.
(8)
Chinese aetiology data from Liu et al. found that presbyacusis was 54% of non-infectious causes. Reported prevalences for
presbyacusis adjusted upwards accordingly.
(9)
Assumed same proportion bilateral as in rural study: For 15+ dBHTL, 74.3% had bilateral deafness. Unilateral tended to be mild deafness.
In the rural study, for unilateral deafness, 96% mild-moderate, while 90% for those with bilateral deafness
(10)
Assumed same sex ratios as in India.
(11)
Prevalences adjusted for difference in prevalence for 1,2,3 and 0.5,1,2,4 kHz using data from Duijvestijn et al 1999
(12)
No age distributions given in Thai study. Age pattern based on average for 4 SEARO countries (Sri Lanka, India, Indonesia, Myanmar).
8
Global Burden of Disease 2000
9
Global Burden of Disease 2000
Table 3.4: Estimated prevalences childhood onset hearing loss at ages 15-19
15+
26+
31+
41+
61+
81+
UK
1.00
0.13
0.10
0.10
Italy
1.00
0.13
0.10
0.10
Denmark
1.00
0.10
0.10
Finland
1.00
0.20
0.10
AUS
1.00
0.10
0.10
USA NHANES1
1.00
0.13
0.10
BeaverDam
1.00
0.13
0.10
Hispanic
1.50
0.50
China
1.00
0.15
0.12
India (Vellore)
2.00
0.00
India (Vellore 2)
1.58
0.10
0.10
Korea
India (Lucknow
Urban)
11.50
3.31
1.57
0.22
India (Lucknow
Rural
13.10
4.57
2.43
0.35
Nepal
5.57
2.96
OMAN
3.33
0.08
2.00
1.00
0.66
0.10
Indonesia
0.80
0.10
0.08
Myanmar
3.82
0.10
0.05
SriLanka
3.53
0.10
0.10
Thailand
5.40
0.15
0.00
3.02
0.93
0.58
Nigeria
9.3
6.86
10
0.61
Global Burden of Disease 2000
UK
Italy
Denmark
Finland
AUS
USA NHANES1
BeaverDam
Hispanic
China
Korea
India (Vellore)
India (Vellore 2)
India (Lucknow Urban)
India (Lucknow Rural
Nepal
OMAN
Indonesia
Myanmar
SriLanka
Thailand
Nigeria
0
2
4
6
8
10
Age-standardised prevalence (%) at 41+ dBHLT
12
14
Figure 3.1. Estimated age-standardised adult-onset hearing loss prevalence rates,
41+ dBHTL, available population studies.
11
Global Burden of Disease 2000
UK
Italy
Denmark
Finland
AUS
USA NHANES1
BeaverDam
Hispanic
China
Korea
India (Vellore)
India (Vellore 2)
India (Lucknow Urban)
India (Lucknow Rural
Nepal
Indonesia
Myanmar
SriLanka
Thailand
0
0.5
1
1.5
2
2.5
3
3.5
4
Age-standardised prevalence (%) at 61+ dBHLT
4.5
5
Figure 3.2. Estimated age-standardised adult-onset hearing loss prevalence rates,
61+ dBHTL, available population studies.
12
Global Burden of Disease 2000
UK
Italy
Finland
BeaverDam
Hispanic
USA NHANES1
Denmark
AUS
China
China
India (Lucknow Rural
India (Lucknow Urban)
India (Vellore 2)
India (Vellore)
OMAN
Myanmar
SriLanka
Thailand
Nepal
Indonesia
Korea
Nigeria
0
0.5
1
1.5
2
2.5
Male/female ratio at 41+ dBHTL
Figure 3.3. Estimated male/female ratio of age-standardised adult-onset hearing loss
prevalence rates, 41+ dBHTL, available population studies.
4. Disease model for adult-onset hearing loss
The incidence and average duration of moderate or greater hearing loss (41+ dBHTL as defined in
Table 2.2) were estimated for each GBD 2000 epidemiological region from estimates of prevalence
by age and sex using the software program DISMOD II, assuming zero remission rate and a relative
risk of mortality of 1.
There is conflicting evidence between mortality and hearing loss. In a ten year longitudinal analysis of
the NHANES I participants aged 55-74 years at baseline who received hearing examination found
than hearing loss predicts mortality: RR = 1.17 (46), however other studies have reported that after
controlling by age the association disappear. We assume an RR of 1.0.
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Global Burden of Disease 2000
Incidence
of HI
Prevalence
Death
Years lived with disability (YLDs) were calculated for the boxes shaded in grey.
Figure 4.1 Adult-onset hearing loss disease model.
Available treatment includes hearing aids, cochlear implants, and lip reading. Cochlear implants5 are
used by people with severe and profound hearing impairments who obtain negligible benefit from
hearing aids. While cochlear implants result in remission from hearing loss, the use of these is
negligible at the population level, and we assume a remission rate of zero. The effect of hearing aid
use is modelled as a reduction in the severity of hearing loss, and hence a lower disability weight.
YLD for hearing loss are calculated from estimated incidence, average duration and disability weight
(1). Disability weights for hearing loss used in the GBD 1990 study (1) and the Netherlands disability
weights study (47) are shown in Table 4.1. The Australian Burden of Disease study (48) used
modified Dutch weights together with Australian survey information on severity distribution in the
population. The resulting average disability weight is shown in the last column of Table 4.1.
Table 4.1 Disability weights for adult-onset hearing loss
Stage/sequela
GBD 1990
Netherlands Study
Australian Study
Mild hearing loss
0.04
0.02
Moderate hearing loss
0.12
0.12
0.37
0.37
Severe hearing loss
(deafness)
0.333 (indicator
condition)
All levels
0.216 (untreated)
0.168 (treated)
The global coverage of hearing aid use has been estimated to be no more than 10%, skewed
towards developed countries (49). Less than 1% of hearing impaired individuals use hearing aids in
developing countries, while in developed countries the rate ranges from 10% to 40% (see Section 5
below). It is thus important to take into account the average prevalence of hearing aid use by region
in calculating the average disability weight for hearing loss. Little information is available on the
impact of hearing aid use on hearing disability. We provisionally assume that hearing aid use reduces
the disability weight to the next lower severity level as shown in Table 4.2. While we give zero
5 It is a device designed to provide sound detection and improved speech understanding
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Global Burden of Disease 2000
disability weight to untreated mild hearing loss, we give a residual weight of 0.04 (the Dutch weight
for mild hearing loss) to a person with moderate hearing loss who uses a hearing aid.
These provisional weights will be revised following analysis of the health state valuation data
collected in the World Health Survey in 2002-2003.
Table 4.2 Provisional disability weights for adult-onset hearing loss, GBD 2000 (Version 2)
Stage/sequela
Disability
weight
Mild (26-40 dBHTL) untreated
0.00
Moderate (41-60 dBHTL) untreated
0.12
Dutch weight for moderate hearing loss
Severe and profound hearing loss
(61+ dBHTL) untreated
0.333
GBD weight for deafness as indicator condition
(Dutch weight is 0.37)
Moderate (41-60 dBHTL) with hearing aid
0.04
Dutch weight for mild hearing loss (25-44
dBHTL)
Severe and profound hearing loss
(61+ dBHTL) with hearing aid
0.12
Dutch weight for moderate hearing loss (45-64
dBHTL)
Comment
5. Treatment for hearing impairment
Studies measuring prevalence of hearing aid use were reviewed (5,15,16,19,21,48,50-69) and used
to estimate the prevalence of hearing aid use among individuals with hearing impairment (assuming
that hearing aid use is confined to moderate impairment levels and greater. The results are shown in
Table 5.2 below.
Table 5.2 Estimated regional prevalence of hearing aid use among those with hearing loss, by severity level, age
and sex, GBD 2000 (Version 3)
Severity
(dBHTL)
41-60
AMRO A
AMRO B AMRO D EURO A EURO B1 EUR B2 EUR C
WPRA
Other
regions
15-29
5
0
0
5
5
0
0
0
0
30-44
10
0
0
5
5
0
0
20
0
45-59
20
3
3
10
10
3
3
30
0
60-69
20
3
3
10
10
3
3
30
0
70-79
20
3
3
10
10
3
3
30
0
15-29
5
0
0
5
5
0
0
5
0
30-44
10
0
0
5
5
0
0
10
0
45-59
20
3
3
10
10
3
3
20
0
Male
Female
15
Global Burden of Disease 2000
61-80
81+
60-69
20
3
3
20
20
3
3
20
0
70-79
20
3
3
30
30
3
3
20
0
Male 15+
50
10
10
50
50
10
10
75
0
Female 15+ 50
10
10
50
50
10
10
50
0
Male 15+
80
25
25
80
80
25
80
80
0
Female 15+ 80
25
25
80
80
25
80
80
0
16
Global Burden of Disease 2000
Age-sex-region specific estimates of prevalence of hearing loss at each of the severity levels (see
Section 6 below) were combined with the estimated prevalence of hearing aid use (Table 5.2) to
compute average disability weights by age, sex and region for hearing loss at levels 41 dBHTL and
higher. The average disability weights thus vary by age and sex across regions. The resulting average
disability weights are summarized below in Table 5.3.
Table 5.3 Estimated average disability weight for ages 15+, by subregion and sex
Subregion
Male
Female
Subregion
Male
Female
AFRO D
0.19
0.20
EURO B2
0.17
0.17
AFRO E
0.19
0.20
EURO C
0.16
0.16
AMRO A
0.13
0.14
SEARO B
0.15
0.17
AMRO B
0.15
0.17
SEARO D
0.16
0.16
AMRO D
0.15
0.17
WPRO A
0.11
0.14
EMRO B
0.18
0.18
WPRO B1
0.19
0.19
EMRO D
0.18
0.18
WPRO B2
0.17
0.19
EURO A
0.13
0.13
WPRO B3
0.17
0.19
EURO B1
0.13
0.13
6. Regional incidence and prevalence estimates
Tables 6.1 and 6.2 summarise the data and assumptions used to estimate regional prevalence rates
for children and adults. For those regions with no available hearing loss prevalence studies,
prevalence rates were assumed to be similar to other selected regions.
Table 6.1 Data and assumptions used to estimate regional prevalence rates for child-onset hearing loss
AFRO D and E
From Nigeria study. Prevalences for 26+ dB assumed similar to SEARO D
AMRO A
Based on prevalences estimated for WPRO A and NHANES III data
AMRO B and D
Based on prevalences estimated for WPRO A, NHANES III and HHANES
EMRO B and D
Prevalences from Oman study. For 81+ dB, assume similar to other regions
EURO A
Based on study prevalences, plus other studies of congenital deafness and
childhood deafness
EURO B1 and C
Assumed the same as Euro A
EURO B2
Based on average of prevalences for Euro B1 and Emro B
SEARO B
Average for India, Indonesia and Vietnam. Prevalences for 26+ dBHTL based on
application of India ratios 26+/41+to average for 41+ from the three studies
SEARO D
Based on India (Vellore 2). Prevalences for 26+ dBHTL based on average of India
(urban) and India (rural) ratios of 26+/41+ applied to 41+ prevalences
WPRO A
Based on Australian study
WPRO B1
Weighted average of China, Korea and Vietnam data. Inclusion of Vietnam to
represent southern and rural areas of China.
17
Global Burden of Disease 2000
WPRO B2
Based on average of Indonesia, Myanmar, Vietnam and India. As Indonesia and
Myanmar have very high prevalences, conservative estimates were made giving
these lower weight in the average. Prevalences for 26+ dBHTL based on application
of India ratios 26+/41+ to 41+ prevalences
WPRO B3
No information. Have used an average of WPRO B1/B2 and SEARO B/D plus (0.5)
weighted AFRO.
18
Global Burden of Disease 2000
Table 6.2 Data and assumptions used to estimate regional prevalence rates for adults
AFRO D and E
Based on Nigerian study
AMRO A
Based on NHANES (using information also from Beaver Dam)
AMRO B and D
Based on Hispanic HANES
EMRO B and D
Based on Oman
EURO A
Population-weighted average of prevalences for Britain, Italy, Denmark and Finland
EURO B1 and C
Assumed the sam e as Euro A
EURO B2
Based on average of prevalences for Euro B1 and Emro B
SEARO B
Average for India, Indonesia and Vietnam. Prevalences for 26+ dBHTL based on
application of India ratios 26+/41+to average for 41+ from the three studies
SEARO D
Based on India (Vellore 2). Prevalences for 26+ dBHTL based on average of India
(urban) and India (rural) ratios of 26+/41+ applied to 41+ prevalences
WPRO A
Based on Australian study
WPRO B1
Weighted average of China, Korea and Vietnam data. Inclusion of Vietnam to
represent southern and rural areas of China.
WPRO B2
Based on average of Indonesia, Myanmar, Vietnam and India. As Indonesia and
Myanmar have very high prevalences, conservative estimates were made giving
these lower weight in the average. Prevalences for 26+ dBHTL based on application
of India ratios 26+/41+ to 41+ prevalences
WPRO B3
No information. Have used an average of WPRO B1/B2 and SEARO B/D plus (0.5)
weighted AFRO.
The resulting overall global prevalences of hearing loss at various threshold levels are shown below in
Table 6.3. There are an estimated 588 million persons (including children) with mild or greater
hearing loss globally, an estimated 248 million with moderate or greater hearing loss, and 53 million
with severe or profound hearing loss. Figure 6.1 shows the resulting regional prevalences for
moderate or greater hearing loss and the age-specific prevalence rates by regional groupings.
Table 6.3 Estimated global prevalence of hearing loss, GBD 2000 (Version 2)
Severity (dBHTL)
Males
Females
Persons
Miild or greater
(26+)
Adult-onset
215
197
413
Child-onset
89
86
175
304
284
588
Adult-onset
94
93
187
Child-onset
31
31
61
125
123
248
21
25
46
Total
Moderate or
greater (41+)
Total
Severe or
greater (61+)
Adult-onset
19
Global Burden of Disease 2000
Child-onset
3
3
7
24
29
53
Adult-onset
3
5
8
Child-onset
3
3
6
Total
6
8
14
Total
Profound (81+)
20
Global Burden of Disease 2000
Prevalence - Females
Prevalence - Males
AFRO D - 1
AFRO D - 1
AFRO E - 2
AFRO E - 2
AMRO A - 3
AMRO A - 3
AMRO B - 4
AMRO B - 4
AMRO D - 5
AMRO D - 5
EMRO B - 6
EMRO B - 6
EMRO D - 7
EMRO D - 7
EURO A - 8
EURO A - 8
EURO B1 - 9
EURO B1 - 9
EURO B2 -10
EURO B2 -10
EURO C -11
EURO C -11
SEARO B -12
SEARO B -12
SEARO D -13
SEARO D -13
WPRO A -14
WPRO A -14
WPRO B1-15
WPRO B1-15
WPRO B2-16
WPRO B2-16
WPRO B3-17
WPRO B3-17
0
0
1,000 2,000 3,000 4,000 5,000 6,000 7,000
Age-std prevalence/100,000
Age-std prevalence/100,000
60000
70000
A Regions
A Regions
Males
50000
EURO BC
EURO BC
EMRO
EMRO
50000
SEARO
SEARO
40000
Prevalence/100,000
WPRO B
AFRO
40000
Females
AMRO BD
AMRO BD
60000
Prevalence/100,000
1,000 2,000 3,000 4,000 5,000 6,000 7,000
30000
WPRO B
AFRO
30000
20000
20000
10000
10000
0
0-4
5-14
15-29 30-44 45-59 60-69 70-79
0
80+
0-4
Age groups
5-14 15-29 30-44 45-59 60-69 70-79
80+
Age groups
Figure 6.1. Estimated adult-onset hearing loss prevalence rates, 41+ dBHTL, by region and sex, GBD 2000
Version 2.
21
Global Burden of Disease 2000
Table 6.3. Adult-onset hearing loss (41+ dBHTL): age-standardized incidence and prevalence estimates for
WHO epidemiological subregions, 2000.
Age-std. Incidence/100,000
Subregion
Males
Females
Age-std. prevalence/100,000
Males
Females
AFRO D
213.8
167.8
3466.8
2919.3
AFRO E
203.9
169.2
3451.1
2976.7
AMRO A
323.1
189.0
4351.5
2643.0
AMRO B
264.7
150.1
3500.9
2119.8
AMRO D
260.3
150.8
3498.1
2107.9
EMRO B
324.2
281.3
4829.5
4200.5
EMRO D
322.8
279.1
4829.0
4241.4
EURO A
234.9
190.0
3337.6
2795.5
EURO B1
233.8
189.7
3301.7
2803.7
EURO B2
273.0
228.9
4037.9
3557.5
EURO C
274.8
235.0
4078.6
3561.7
SEARO B
421.8
336.7
6390.3
4901.9
SEARO D
363.2
360.0
5870.1
5827.1
WPRO A
243.1
187.7
2859.6
2685.9
WPRO B1
159.5
127.4
2567.5
2056.6
WPRO B2
430.7
346.4
6352.3
4506.2
WPRO B3
326.8
278.1
5081.0
4163.0
World
271.5
220.1
4036.3
3326.7
•
Age-standardized to World Standard Population.
22
Global Burden of Disease 2000
7. Global burden of adult-onset hearing loss in 2000
General methods used for the estimation of the global burden of disease are given elsewhere (50).
The tables and graphs below summarise the global burden of adult-onset hearing loss estimates for
the GBD 2000. Total global YLD for hearing loss are estimated to be 24.9 million or 4.7% of total
YLD due to all causes. This makes hearing loss the second leading cause of YLD after depression,
and gives it a larger non-fatal burden than alcohol use disorders, osteoarthritis and schizophrenia.
Table 7.1. Adult-onset hearing loss: YLD, YLL and DALY estimates by subregion, 2000.
YLD/100,000
Subregion
YLL/100,000
YLD
YLL
(‘000)
(‘000)
DALY
Males
Females
Males
Females
AFRO D
304.2
299.8
0.0
0.0
1,008
0
1,008
AFRO E
301.6
285.6
0.0
0.0
991
0
991
AMRO A
475.1
357.4
0.0
0.0
1,286
0
1,286
AMRO B
277.7
222.7
0.0
0.0
1,106
0
1,106
AMRO D
221.4
171.4
0.0
0.0
140
0
140
EMRO B
409.5
358.1
0.0
0.0
537
0
537
EMRO D
383.0
399.5
0.0
0.0
540
0
540
434.3
0.0
0.0
1,818
0
1,818
0
550
EURO A
450.9
(‘000)
EURO B1
328.6
334.3
0.0
0.0
550
EURO B2
352.8
383.4
0.0
0.0
188
0
188
EURO C
479.0
550.8
0.0
0.0
1,271
0
1,271
SEARO B
570.0
453.7
0.0
0.0
2,019
0
2,019
SEARO D
514.4
551.3
0.0
0.0
7,177
0
7,177
WPRO A
337.0
451.6
0.0
0.0
591
0
591
WPRO B1
386.9
352.2
0.0
0.0
5,025
0
5,025
427.9
0.0
0.0
644
0
644
0
25
0
24,915
WPRO B2
479.7
WPRO B3
394.4
346.7
0.0
0.0
25
World
420.5
403.7
0.0
0.0
24,915
8. Conclusions
These are version 3 estimates for the GBD 2000 as published in the World Health Report 2003.
Apart from uncertainty analysis, updating estimates to reflect revisions of mortality estimates and any
new or revised epidemiological data or evidence, it is not intended to undertake any major addition
revision of these estimates.
We welcome comments and criticisms of these draft estimates, and information on additional sources
of data and evidence.
23
Global Burden of Disease 2000
Acknowledgements
We particularly wish to thank Christina Bernard and Jennifer Wong for assistance with literature
reviews, DISMOD analyses and preparation of this paper.
24
Global Burden of Disease 2000
MALES - YLD per 1,000
World
GBD 2000
MEC - EMRO B+D
GBD 1990
LAC - AMRO B+D
SSA - AFRO D+E
OAI - SEARB+WPRB2/3
CHI - WPRO B1
IND - SEARO D
FSE - Euro B+C
EME - A regions
0.00
1.00
2.00
3.00
YLD/1000
4.00
5.00
6.00
FEMALES - YLD per 1,000
World
GBD 2000
MEC - EMRO B+D
GBD 1990
LAC - AMRO B+D
SSA - AFRO D+E
OAI - SEARB+WPRB2/3
CHI - WPRO B1
IND - SEARO D
FSE - Euro B+C
EME - A regions
0.00
1.00
2.00
3.00
4.00
5.00
6.00
YLD/1000
Figure 7.1. Adult-onset hearing loss YLD rates, by sex, broad regions, 1990 and 2000.
25
Global Burden of Disease 2000
MALES - Global YLD per 1,000 by age
14.00
GBD 1990
12.00
GBD 2000
YLD/1000
10.00
8.00
6.00
4.00
2.00
0.00
0
20
40
60
80
100
FEMALES - Global YLD per 1,000 by age
14.00
GBD 1990
12.00
GBD 2000
YLD/1000
10.00
8.00
6.00
4.00
2.00
0.00
0
20
40
60
80
100
Figure 7.2. Global adult-onset hearing loss YLD rates, by age and sex, 1990 and 2000.
26
Global Burden of Disease 2000
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