Download Prevalence of Childhood Hearing Loss: The Hispanic Health and

American Journal of Epidemiology
Copyright © 1996 by The Johns Hopkins University School of Hygiene and Public Health
All rights reserved
Vol. 144, No. 5
Printed In U.S.A
ORIGINAL CONTRIBUTIONS
Prevalence of Childhood Hearing Loss
The Hispanic Health and Nutrition Examination Survey and the National Health and
Nutrition Examination Survey II
David J. Lee, 12 Orlando Gomez-Mann,1'3 and Heidi M. Lee4
Comparative analysis of the epidemiology of childhood hearing loss was undertaken among AfricanAmerican, Hispanic-American, and non-Hispanic white children. Audiometric data on children aged 6-19 years
were obtained from 688 African Americans, 330 Cuban Americans, 2,602 Mexican Americans, 1,025 Puerto
Ricans, and 3,243 non-Hispanic whites who participated in either the National Health and Nutrition Examination Survey II, 1976-1980, or the Hispanic Health and Nutrition Examination Survey, 1982-1984. Hearing
loss was defined as a pure-tone decibel hearing threshold level (averaged over 500, 1,000, and 2,000 Hz)
greater than 15 in the ear with the best response. The prevalence (per 1,000) of bilateral hearing loss was 17.0
for African-American, 68.3 for Cuban-American, 27.6 for Mexican-American, 57.7 for Puerto Rican, and 15.5
for non-Hispanic white children. Differences in prevalence by ethnicity/race diminished when a more stringent
definition of hearing loss (i.e., moderate or greater than 30 dB hearing threshold level) was used. There were
no adolescent African-American males aged 16-19 years who had a hearing loss. After adjustment for age, the
odds of hearing loss was significantly greater in males than in females only in non-Hispanic whites (odds
ratio = 2.2; 95% confidence interval 1.6-3.3). On the basis of 1993 census population estimates in the United
States, over 819,000 children aged 6-19 years have some degree of hearing impairment, and over 216,000 of
these children have moderate or greater hearing impairment. Am J Epidemiol 1996; 144:442-9.
blacks; child; hearing loss, bilateral; Hispanic Americans; whites
There are several published reports from national
population-based audiometric surveys of non-Hispanic
white and African-American children (1-4), but there
are no comparable reports for the US Hispanic population. Comparative analyses of the epidemiology of
childhood hearing loss among African-American, Hispanic-American, and non-Hispanic white American
children have not been undertaken, nor have estimates
been published of the number of hearing-impaired
children residing in the United States. Furthermore,
previously published prevalence estimates for US children have utilized definitions of hearing loss developed for adults (5). These definitions have been criticized for their inability to identify mild levels of
hearing loss in children. In children, lower hearing
threshold levels are clinically relevant, given the critical relation between hearing loss and language acquisition (6-8). Mild hearing loss levels, which fail to
meet the threshold for traditional definitions of hearing
loss in adults, may also be associated with poor scholastic performance in children (9).
This report examines the prevalence of hearing loss
in children aged 6-19 years by using data from the
Hispanic Health and Nutrition Examination Survey
(HHANES) (10) and the National Health and Nutrition
Examination Survey II (NHANES II) (11).
Received for publication July 21, 1995, and in final form June 6,
1996.
Abbreviations: Cl, confidence interval; dBHL, decibel hearing
threshold level; HHANES, Hispanic Health and Nutrition Examination Survey; NCHS, National Center for Hearth Statistics; NHANES
II, National Health and Nutrition Examination Survey II.
1
Department of Epidemiology and Public Health, University of
Miami School of Medicine, Miami, FL
2
Department of Otolaryngology, University of Miami School of
Medicine, Miami, FL
3
Department of Pediatrics, University of Miami School of Medicine, Miami, FL
4
Department of Speech Pathology and Audiology, Miami Children's Hospital, Miami, FL.
Reprint requests to Dr. David J. Lee, Department of Epidemiology and Public Health, P. O. Box 016069 (R-669), Miami, FL 33101.
MATERIALS AND METHODS
Study population and design
The HHANES, conducted in 1982-1984 by the National Center for Health Statistics (NCHS), used a
complex multistage sampling design, obtaining a rep442
Prevalence of Childhood Hearing Loss
resentative sample of Mexican Americans from the
southwestern states (Texas, New Mexico, Colorado,
Arizona, and California), Cuban Americans from the
Miami area, and Puerto Ricans from the New York
City area (10, 12). The sampling design employed
assured an 87 percent representation of the population
of Mexican origin in these five southwestern states as
well as 84 percent of all persons of Mexican origin in
the United States (12). The HHANES was representative of 96 percent of the Cuban-American population
in the Miami, Florida, area and was representative of
57 percent of the population of Cuban origin in the
United States. The Puerto Rican portion of the survey
was representative of 90 percent of this population in
the New York City area and of 59 percent of the US
Puerto Rican population. Overall, the three Hispanic
groups included in the HHANES are representative of
approximately 76 percent of the 1980 US population
of Hispanic origin. A small percentage of participants
originally misidentified as being of Hispanic origin
were excluded from this analysis. Informed consent
was obtained from all participants or their parents.
The NHANES H, conducted in 1976-1980 by the
NCHS, also used a complex sample design, obtaining
a nationally representative sample of African Americans and whites (11). In this survey, race was ascertained by the interviewer, who was instructed to record
race as "white," "black," or "other." Those identified
as other were excluded from this analysis. Participants
(or their parents) were asked to identify their country
of origin. Children identified as being of "Chicano,"
"Cuban," "Mexican," "Mexicano," "Mexican American," or "Puerto Rican" origin were excluded from
this analysis (n = 278). Informed consent was obtained from all participants or their parents.
Data collection for the HHANES and the NHANES
II took place in two phases. Participants were first
administered a household interview. Next, they were
given a comprehensive physical examination at centrally located examination trailers. Overall response
rates for participating in the household interview and
attending the physical examination, where audiometric
data were collected, were 61, 76, and 75 percent,
respectively, for Cuban Americans, Mexican Americans, and Puerto Ricans (10). Response rates for the
NHANES II were 76 percent for African Americans
and 73 percent for whites (13).
Our analyses are limited to children aged 6-19
years. Participants with incomplete audiometric data
(n = 41) and those who were tested during possible
audiometric equipment malfunction (n = 19) were
excluded from these analyses. Complete pure-tone audiometric data were collected on 688 African Americans, 330 Cuban Americans, 2,602 Mexican AmeriAw J Epidemiol
Vol. 144, No. 5, 1996
443
cans, 1,025 Puerto Ricans, and 3,243 non-Hispanic
whites.
Hearing measures
Audiometric testing was conducted in the NHANES
II and the HHANES using similar methodology (14,
15), including the same calibration specifications for
audiometric equipment (16). Identical equipment was
used in the studies, including audiometers (model
200-C, Beltone, Chicago, Illinois), sound level meters
(model 2203, BrYel & Kjar, Decatur, Georgia), artificial ear couplers (BrYel & Kjar model 4151), condenser microphones (BrYel & Kjar model 4144), octave band filters (BrYel & Kjar model 1613), and
acoustic calibrators (BrYel & Kjar model 4230). Airconduction thresholds were obtained in sound-treated
rooms at 500, 1,000, 2,000, and 4,000 Hz, with testing
repeated at 1,000 Hz. Masked thresholds were obtained when there was an interear difference in airconduction thresholds of greater than 40 dB hearing
threshold level (dBHL) (14, 15).
Pure-tone averages were calculated by averaging
thresholds obtained at frequencies of 500, 1,000, and
2,000 Hz (6). The better (i.e., lower) of the two threshold responses at 1,000 Hz was used in calculation of
pure-tone average. Masked threshold values were used
when appropriate. Overall hearing loss was defined as
a pure-tone average of greater than 15 dBHL in the ear
with the better (i.e., lower) hearing sensitivity (6).
Slight-to-mild hearing loss was defined as a pure-tone
average 16-30 dBHL, and moderate or greater hearing
loss was defined as a pure-tone average that exceeded
30 dBHL (6).
Prior to completing our primary analyses, we sought
to determine the influence of nonparticipation in the
physical examination during which the audiometric
testing took place. During the HHANES household
examination, the children or their parents were asked:
1) "Have you ever had trouble hearing with one or
both ears? Do not include any problems which lasted
just a short period of time such as during a cold," or 2)
"Has [the sample person] ever had trouble hearing
with one or both ears? Do not include any problems
which lasted just a short period of time such as during
a cold." The NHANES II interview includes similar
questions except that the words "deafness or" preceded the words "trouble hearing." We coded participants as having self-reported hearing difficulties if a
positive response was given to either of these questions.
Prevalence rates of self-reported hearing loss were
then compared to determine whether those who reported hearing difficulties were more or less likely to
444
Lee et a).
attend the physical examination where audiometric
testing was completed.
20 percent to obtain an estimate of the number of
children aged 6-9 years. This assumes that the age
distribution in 5- to 9-year category is uniform.
Statistical analysis
Because of the multistage sampling design, all analyses were performed with adjustments for sample
weights and design effects by using the SUDAAN
statistical package for analysis of complex sample
surveys (10, 17).
Prevalence rates of hearing loss (per 1,000) and 95
percent confidence intervals were reported for all comparisons. Ninety-five percent confidence intervals
were calculated using standard error estimates with a
level of precision of 100. Prevalence rates and confidence intervals were then rounded to the nearest one
tenth prior to being reported. Any two prevalence rates
whose 95 percent confidence intervals did not overlap
were considered significantly different at the 5 percent
level. To allow for comparisons across ethnic groups,
we adjusted prevalence rates for age and gender by
using the direct adjustment method via the 1993 US
population distribution for children aged 6-19 years as
the standard (18).
Logistic regression was used to estimate the odds of
hearing loss in males versus females after controlling
for age. Prior to completing these analyses, interactions between age and gender were examined.
Estimates of the number of hearing-impaired AfricanAmerican, Cuban-American, Mexican-American, Puerto Rican, and non-Hispanic white children residing in
the United States were derived by applying prevalence
rates to the race-/ethnic-specific estimates of the number of children residing in the United States. We
selected 1993 projected population data that provide
the most recent estimates of the number Hispanics and
non-Hispanics residing in the United States (18, 19).
Because published census estimates for Hispanic children were reported only in 5-year age intervals (i.e.,
5-9, 10-14, and 15-19 years), we reduced the published number of Hispanic children aged 5—9 years by
RESULTS
Table 1 presents the rate (per 1,000) of serf-reported
hearing loss in participants who did and those did not
complete audiometric testing. For each ethnic group,
self-reported hearing loss rates were higher in those
who completed audiometric testing. However, these
differences were significant only for Cuban Americans. Reported hearing ioss rates in Cuban Americans
who completed testing were over six times higher than
in those who did not complete testing.
Table 2 presents the prevalence of hearing loss by
ethnicity and severity of hearing loss. Also presented
are ethnicity-specific rates adjusted for age and gender. The prevalence of slight/mild hearing loss (16-30
dBHL) ranged from 9.4 per 1,000 in AfricanAmerican children to 56.6 per 1,000 in Cuban-American children. Cuban-American and Puerto Rican children had significantly higher age- and gender-adjusted
rates of slight/mild hearing loss than did AfricanAmerican, Mexican-American, and non-Hispanic
white children. Cuban-American children also had a
significantly higher prevalence of hearing loss than did
Mexican-American children. Prevalence rates for
moderate and greater hearing loss (>30 dBHL) ranged
from 3.7 per 1,000 in non-Hispanic whites to 11.7 per
1,000 in Cuban Americans. There were no statistically
significant differences in the age- and gender-adjusted
prevalence of moderate and greater hearing loss. Prevalence rates of overall hearing loss (>15 dBHL)
ranged from 15.5 per 1,000 in non-Hispanic whites to
68.3 per 1,000 in Cuban Americans. The latter ethnic
group had an age- and gender-adjusted prevalence rate
that was significantly higher than the rates for all other
groups with the exception of the rate for Puerto
Ricans. The rate for Puerto Rican children was also
TABLE 1. Ethnic-specific prevalence rates (per 1,000) of self-reported hearing loss by examination
status: results from the Hispanfo Health and Nutrition Examination Survey, 1982-1984, and the
National Health and Nutrition Examination Survey II, 1976-1980
Old not complete audiometric testing
t i m e group
African American
Cuban American
Mexican American
Puerto Rican
White, non-Hispanic
Completed audiometric testing
Prevalence4
95%Clt
Prevalence*
95% Cl
27.0
10.4
54.3
47.2
60.4
0.0-54.3
0.0-29.5
27.2-81.3
8.6-85.9
41.9-79.0
39.8
67.3
72.7
87.3
66.3
28.3-51.4
41.8-92.8
57.5-87.9
67.7-104.9
55.0-77.5
* Rates adjusted for sample weights and design effects. Because of dfferences in question wording in the
two surveys, comparison of prevalence rates in Hispanics and non-Hispanics should not be undertaken,
t Cl, confidence interval.
Am J Epidemiol Vol. 144, No. 5, 1996
Prevalence of Childhood Hearing Loss
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Am J Epidemiol
Vol. 144, No. 5, 1996
significantly higher than those for all other ethnic
groups with the exception of Cuban Americans.
Table 3 presents the ethnic-/gender-specific prevalence rates of hearing loss (>15 dBHL) by age group
(6-10, 11-15, and 16-19 years). Because of the small
sample sizes, confidence intervals for most prevalence
estimates are wide. There was a trend toward lower
prevalence rates with increasing age groups among
males, but not generally among females. However, in
part due to large standard errors, none of the differences in prevalence of hearing loss in males were
statistically significant across age group categories.
There were no consistent associations between gender and hearing loss when the age-adjusted odds ratios
for gender among the five ethnic groups were compared. However, non-Hispanic white males had a significantly higher prevalence of hearing loss than did
their female counterparts (odds ratio = 2.3, 95 percent
confidence interval (CI) 1.6-3.3). There was a significant interaction between age and gender when prevalence rates among Puerto Ricans were compared.
This analysis was repeated in two subgroups of Puerto
Ricans who were below the median age (6-12 years)
and those who were at or above the median age (13-19
years). It was first confirmed that there were no
age-by-gender interactions in each of these two age
groups. Males in the age group 6-12 years had higher
rates of hearing loss than did females. This difference
in rates by gender approached statistical significance
(odds ratio = 2.5, 95 percent CI 1.0-6.6). In the older
age group, females had higher rates of hearing loss
than did males. These differences, however, were not
statistically significant (odds ratio = 0.4, 95 percent
CI 0.1-1.2).
Table 4 presents the estimates of the number (in
thousands) of African-American, Cuban-American,
Mexican-American, Puerto Rican, and non-Hispanic
white children aged 6-19 years in the United States by
hearing loss severity and ethnicity. Approximately
819,000 children have a bilateral hearing loss of
greater than 15 dBHL. The majority of these children
(approximately 603,000) have a slight/mild hearing
loss.
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To our knowledge, this is the first published study to
complete a comparative analysis of the prevalence of
childhood hearing loss among the major ethnic/racial
groups in the United States. The most noteworthy
finding of these analyses is the higher prevalence of
hearing loss among Hispanics when compared with
African Americans and non-Hispanic whites. These
differences were particularly striking for CubanAmerican and Puerto Rican children, who had rates of
446
Lee et al.
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hearing loss (> 15 dBHL) that were three to four times
greater than those among African Americans and nonHispanic whites. These differences, were, however,
largely due to the higher prevalence of slight/mild
hearing loss (16-30 dBHL). Nevertheless, the highest
prevalence of moderate or greater hearing loss was
found among Cuban Americans and Puerto Ricans.
When prevalence of hearing loss among Hispanics
was compared, Mexican Americans had significantly
lower rates of slight/mild and overall hearing loss
relative to the other Hispanic subgroups. The age- and
gender-adjusted rate for moderate or greater hearing
loss was also lowest among Mexican Americans (6.0
per 1,000), although this rate was not significantly
different from the rates for Cuban Americans (12.1 per
1,000) and Puerto Ricans (9.5 per 1,000).
We found only limited evidence that males have
higher rates of hearing loss than do females. Among
non-Hispanic whites, higher rates of hearing loss were
found in males versus females (odds ratio = 2.2, 95
percent CI 1.6-3.3). Higher rates of hearing loss that
approached statistical significance were found for
Puerto Rican males aged 6-12 years (odds ratio = 2.5,
95 percent CI 1.0-6.6). Gender comparisons in other
ethnic/age groups were inconsistent and nonsignificant. Results of other studies have also noted inconsistent differences in frequency responses by gender.
Some studies have reported no differences across a
broad frequency spectrum (i.e., 250-8,000 Hz) (1) or
when using pure-tone thresholds averaged over 5004,000 Hz (20). Other studies have suggested a pattern
of greater hearing loss in males than in females in the
higher frequencies (i.e., >2,000 Hz) (3, 21). However,
the magnitude of these gender differences in the higher
frequencies is not large.
There are several advantages of these analyses over
previously published results. Both surveys used in this
analysis are representative of the US population. The
NHANES II was designed to be a nationally representative study of African Americans and whites, while
the HHANES was designed to be representative of the
Mexican-American population in the southwestern
United States, Cuban Americans in southern Florida,
and Puerto Ricans in the New York City area. Although not designed to be representative of Hispanics
nationwide, the HHANES is representative of 76 percent of the US Hispanic population (12).
The second advantage of these analyses is the similarity of methods used in the two surveys that allowed
comparative analysis of the prevalence of hearing loss
in Hispanics and non-Hispanics. These similarities
included use of the same type of audiometric equipment and audiometric testing procedures. Similarities
in sampling methods and overall testing procedures in
Am J Epidemiol
Vol. 144, No. 5, 1996
Prevalence of Childhood Hearing Loss
447
TABLE 4. Estimated number (in thousands) of hearing-impaired children aged 6-19 years residing In
the United Statea In 1993 by hearing loas severity and ethnicity: results from the Hispanic Health and
Nutrition Examination Survey, 1982-1984, and the National Health and Nutrition Examination Survey II,
1976-1980*
Degree of hearing loss
Sflgrrt/mlldt
(16-30 dB hearing
threshold level)
Ethnic group
No.
African American
Cuban American
Mexican American
Puerto Rican
White, non-Hispanic
69.0
7.7
85.6
32.7
408.3
Total
603.3
95% Cl*
5.8-132.2
5.3-10.1
51.9-119.3
23.4-42.0
203.7-613.0
Moderate and grsaterf
(>30 dB hearing threshold
level)
OvBraOf
(>15dB hearing
threshold level)
No.
95% Cl
No.
95% Cl
56.2
1.6
22.8
6.5
129.0
5.5-106.8
0.2-3.0
14.3-31.3
3.3-9.8
63.2-194.7
125.2
9.3
108.4
39.2
537.3
37.1-213.3
6.4-12.2
72.5-144.4
29.6-48.8
308.9-765.6
216.1
819.4
* Population estimates of the number of Hispanlcs and non-HispanJcs residing In the United States were
derived from 1993 projected population estimates.
t Rates used to calculate population estimates were first adjusted for sample weights and design effects.
t Cl, confidence interval.
the two surveys also suggest that bias introduced by
comparing studies conducted in different populations
is minimized.
There are several limitations of this study that
should be noted. First, we had relatively low statistical
power to detect significant differences in hearing loss
in various subgroups (e.g., gender and age categories).
This was due, in part, to the relatively low prevalence
of hearing loss in children. The NHANES H and
HHANES surveys were not designed to provide stable
estimates of conditions that occur infrequently in the
US population. In addition, overall sample sizes of
African Americans, Cuban Americans, and Puerto
Ricans were relatively small.
Time and cost constraints prevented the inclusion of
bone conduction audiometry in the HHANES and the
NHANES n. Furthermore, immittance measures were
not undertaken in the NHANES n. Immittance measures were assessed in the HHANES, although test
results were never released by the NCHS, in part due
to technical difficulties in reliably completing the procedure. Information obtained by bone conduction audiometry and immittance measures would have allowed the determination of type of hearing loss (i.e.,
sensorineural vs. conductive) and the percentage of
hearing loss that was likely to be temporary (i.e., otitis
media-related hearing loss) versus permanent. For example, the higher rates of mild hearing loss found in
Hispanic children in this study may have been due to
higher rates of otitis media in Hispanics versus nonHispanics. Several researchers have noted a higher
prevalence of otitis media in non-Hispanic whites versus African Americans (22), but research on the prevalence of otitis media in the first 3 years of life has
indicated that the highest prevalence of any ethnic/
Am J Epidemiol
Vol. 144, No. 5, 1996
racial group was found among a small sample of
Hispanics and others not classified as non-Hispanic
white or African American (23). In a follow-up study
of 46 low-birth-weight infants at risk for neurodevelopmental disorders, Hispanic children were more
likely to experience their first episode of otitis media
at a younger age than were African-American children
(24). However, a random sample of pediatric medical
charts in Galveston, Texas, revealed no significant
differences in the incidence of otitis media between
non-Hispanic children aged 0-8 years versus children
with Hispanic surnames (25). Finally, in the 1988
National Health Interview Survey, parents of Hispanic
children were more likely than African-American parents to report multiple "ear infections" in the previous
year (26). However, in this study the highest rates of
multiple ear infection were reported by the parents of
non-Hispanic white children.
These inconsistent findings prevent us from speculating with a high degree of confidence that the higher
rates of slight/mild hearing loss found among Hispanics in this study could be due in part to higher rates of
otitis media in Hispanics versus non-Hispanic whites
and African Americans. As indicated earlier, lack of
bone conduction audiometry and immittance measures
prevented us from testing this hypothesis. Future research on the epidemiology of hearing loss in children
should include these measures as well as pure-tone
audiometry to determine type of hearing loss. Such
information is critical to assess the public health impact of hearing loss as well as to devise effective
prevention strategies.
Potential nonresponse bias to the physical examination during which audiometric data were collected
448
Lee et al.
may be another study limitation. Self-reported lifetime
prevalence of hearing loss was significantly higher in
Cuban-American children who attended their physical
examination versus those who did not. It is therefore
possible that prevalence estimates for CubanAmerican children are overestimates of the "true"
prevalence of hearing loss in this ethnic group. However, we calculated the sensitivity of this self-report
measure in Cuban Americans by using our audiometrically defined measure of overall hearing loss (i.e.,
>15 dBHL) as our "gold standard." We found a
sensitivity of only 25 percent, suggesting that lifetime
prevalence of self-reported hearing difficulties is a
poor predictor of current hearing loss. Nevertheless,
the finding that Cuban-American children who reported a lifetime history were more Likely to have
attended their physical examination raises the strong
possibility that at least a portion of the elevated rates
of audiometrically confirmed hearing loss found in
Cuban-American children is due to nonresponse bias.
This possibility, in conjunction with the small sample
size used to estimate prevalence in this ethnic group,
suggests that additional research is needed to provide
more accurate estimates of hearing loss in CubanAmerican children.
It is unknown whether nonresponse to the household
interview was also influenced by self-reported hearing
difficulties identified by the children or their parents.
However, one study of the influence of nonresponse to
the NHANES II household interview on prevalence of
selected health conditions in adults has been undertaken (27). This study compared questionnaire responses from the 1976 National Health Interview
Survey, which had a very low percentage of nonrespondents (i.e., less than 4 percent), with similar questionnaire items asked during the NHANES II household interview. Two items included in this analysis
were "deafness" and "ear infections." There were no
differences in the percentages of respondents who
replied positively to two these questions in the two
surveys, suggesting that the NHANES II nonresponse
was not influenced by concerns over ear infections or
severe hearing problems. Unfortunately, this analysis
was limited to adults aged 20-74 years. It is not
known whether similar results hold also for children.
It should also be reiterated that all prevalence estimates in this analysis were adjusted using weights
provided by NCHS. These weights adjust for nonresponse and noncoverage within primary sampling
units (12). More specifically, these weights adjust for
nonresponse to the household interview and to the
examination during which audiometric testing was
completed. Furthermore, a recently completed com-
prehensive analysis of nonresponse bias in the
HHANES suggested that while response rates were
higher in those with a health care need or condition,
this response pattern was unlikely to cause significant
bias in prevalence estimates (28).
Finally, differences in prevalence rates in Hispanics
versus non-Hispanics may be due to trends in hearing
loss rates in children. Since the NHANES II was
conducted in 1976-1980 and the HHANES in 19821984, it is possible that higher rates of hearing loss
reported for Hispanics could be due to increasing
prevalence of hearing loss in the US population over
time. However, there has been little increase in the
prevalence of self-reported hearing loss in children
noted in the National Health Interview Surveys. For
example, the prevalence (per 1,000) of any degree of
hearing impairment increased from 16.2 in 1971 to
18.2 in 1990-1991 (29). Extrapolating from these
self-report data, it is therefore unlikely that the significant differences in prevalence rates in non-Hispanics
versus Hispanics reported in this paper can be explained in large part by any trends from 1976-1980 to
1982-1984.
Hearing loss was defined in this analysis as bilateral
threshold responses that exceeded 15 dBHL averaged
over three frequencies: 500, 1,000, and 2,000 Hz. This
threshold is lower than that which is typically used for
adults and was selected because of concerns that lower
levels of hearing loss may adversely affect language
acquisition and perhaps educational achievement (6,
7). Evidence to support an association between mild
hearing loss and these outcomes is limited and has
been criticized on methodological grounds (9). Additional research is needed to determine age-specific
optimal audiometric thresholds that correlate with outcomes of public health importance such as language
acquisition, educational achievement, and psychologic
well-being.
To summarize, this paper found significantly higher
rates of hearing loss in Cuban-American and Puerto
Rican than in African-American, Mexican-American,
and non-Hispanic white children. These differences
were largely due to a higher prevalence of slight/mild
(16-30 dBHL) hearing loss in these two Hispanic
groups. There were no consistent differences in prevalence of hearing loss by age or gender across the five
ethnic/racial groups. Additional research is needed to
determine the type of hearing loss (i.e., conductive vs.
sensorineural). Finally, additional research is needed
to confirm the high prevalence estimates reported for
Cuban-American and Puerto Rican children and to
identify factors that account for higher rates of hearing
loss in these Hispanic populations.
Am J Epidemiol
Vol. 144, No. 5, 1996
Prevalence of Childhood Hearing Loss
ACKNOWLEDGMENTS
Supported by grant 1 R03 DC 02073-01 from the National Institute on Deafness and Other Communication Disorders.
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