Page 25 - IJPS-8-1

International Journal of
Population Studies Hearing loss, hearing aids, and cognitive function

to estimate (1) the within-individual change in cognitive and (iv) poor hearing, aided. For White older adults, worse
function with age and (2) the between-person differences self-rated hearing (P < 0.001) and wearing a hearing aid
in baseline cognitive function (intercept) and the change in (P < 0.001) were associated with lower cognitive scores
cognitive function (slope) with increasing age. Preliminary at age 65 compared to those who reported better hearing
tests of model fit indicated that a quadratic function or wearing a hearing aid, respectively. White participants
best parameterized the age-related patterns of cognitive with excellent (unaided) hearing had an average cognitive
decline among older adults – a finding that is consistent score of 24.8 at age 65, compared to 23.9 for excellent
with prior research (Cloutier, Chertkow, Kergoat, et al., (aided), 23.8 for poor (unaided), and 23.0 for poor (aided)
2015; Maharani, Dawes, Nazroo, et al., 2019). Preliminary among White participants. Results also showed that the
analyses also indicated significant racial/ethnic differences differences in cognitive function associated with self-rated
in hearing and/or cognitive function; therefore, the mixed hearing and wearing a hearing aid diminished at later ages.
models were estimated separately in each racial/ethnic For Black older adults, worse self-rated hearing
group. Bayesian Information Criteria (BIC) and Akaike (P < 0.001) was associated with lower cognitive scores at
Information Criteria (AIC) statistics indicated that a age 65 compared to those who reported better hearing.
quadratic function remained the best model fit for all The use of hearing aids was not significantly associated
three groups. Differences by sex were also assessed and no with cognitive function in Black participants (P = 0.52).
significant interactions were found. In Figure 2, Black older adults with excellent (unaided)
All mixed models included adjustments for sex, hearing had an average cognitive score of 20.9, compared
marital status, household size, geographic region, to 20.8 for those with excellent (aided) hearing, 19.6 for
education, employment, wealth, smoking status, alcohol poor (unaided), and 19.5 for poor (aided). Consistent with
consumption, ADLs, disease diagnoses, and indicators the finding for White older adults, the association between
for mortality/attrition. We also tested for interactions self-rated hearing and cognition declined among Black
among age, hearing loss, and hearing aid use to account older adults at later ages.
for possible changes in the associations over time. The final For Hispanic older adults, self-rated hearing (P = 0.008)
models retain the significant associations that provided and hearing-aid use (P < 0.001) were associated with lower
the best model fit (assessed by BIC and AIC statistics) for cognitive scores at age 65. Hispanic participants with
each racial/ethnic group. Estimates were then plotted to excellent (unaided) hearing had an average cognitive score
facilitate interpretation. of 20.7, while those with excellent (aided) hearing had
scores of 18.9, those with unaided (unaided) had scores of
3. Results 20.2 and those with poor (aided) had scores of 18.4. Results
Overall sample distributions for the study period also showed that the differences in cognitive function
(1998 – 2018) are shown by race/ethnicity in Table 1. associated with wearing a hearing aid (but not self-rated
Overall, White older adults exhibited significantly higher hearing) diminished at later ages.
cognitive function (22.7, SD = 4.7) compared with Black
(18.9, SD = 5.5) and Hispanic (19.1, SD = 5.2) older adults. 4. Discussion
A larger proportion of Hispanic older adults reported In this brief report, we examined 20 years of longitudinal
hearing loss (fair/poor hearing, 32.4%) than White (22.3%) data to characterize how age-related changes in hearing
and Black (20.1%) older adults. In terms of hearing aid use, loss and hearing aid use were associated with trajectories
a larger proportion of White participants (13.7%) reported of cognitive decline in a large U.S. national sample.
wearing hearing aids compared with both Hispanic (8.3%) Overall, the results suggested that levels of self-reported
and Black (5.5%) participants. More White participants hearing and hearing aid use had complex associations with
died during the study period (39.3%) compared to Black cognitive function that varied across age and across major
(35.2%) and Hispanic (27.7%) participants. racial/ethnic groups in the U.S.
Table 2 presents the results from the mixed models Three major findings were observed. First, White
showing the age-related associations among hearing older adults had overall better cognitive function at all
level, hearing aid use, and cognitive function in White, ages compared with Black and Hispanic older adults.
Black, and Hispanic older adults in the study. To facilitate This finding is consistent with previous research showing
interpretation of the findings, the results from Table 2 are that Black and Hispanic populations are at higher risk for
plotted in Figure 2 for four major categories of hearing developing ADRD compared to White adults (Babulal,
and hearing aid use: (i) excellent hearing, unaided; Quiroz, Albensi, et al., 2019). Second, older adults who
(ii) excellent hearing, aided; (iii) poor hearing, unaided; reported worse hearing had lower levels of cognitive

Volume 8 Issue 1 (2022) 19 https://doi.org/10.36922/ijps.v8i1.1308