Associations between hearing impairment and mortality risk in older persons: the Blue Mountains Hearing Study.
OBJECTIVE
To assess whether hearing loss predicts an increased risk of mortality.


METHODS
The Blue Mountains Hearing Study examined 2956 persons (49+ years) during 1997 to 2000. The Australian National Death Index was used to identify deaths until 2005. Hearing loss was defined as the pure-tone average (0.5-4 kHz) of air-conduction hearing thresholds greater than 25 dB HL. Associations between hearing loss and mortality risk were estimated using Cox regression and structural equation modeling (SEM).


RESULTS
When we used Cox regression, we discovered that hearing loss was associated with increased risk of cardiovascular (hazard ratio [HR] 1.36, 95% confidence interval [CI] 1.08-1.84) and all-cause (AC) mortality (HR 1.39, 95% CI 1.11-1.79) after adjustment for age and sex but not after multivariable adjustment. SEM pathway analysis, however, revealed a greater AC mortality risk (HR 2.58, 95% CI 1.64-4.05) in persons with hearing loss, which was mediated: cognitive impairment (HR 1.45, 95% CI 1.08-1.94) and walking disability (HR 1.63, 95% CI 1.24-2.15). These variables increased mortality both directly and indirectly through effects on self-rated health.


CONCLUSIONS
Hearing loss was associated with increased AC mortality via three mediating variables: disability in walking, cognitive impairment, and self-rated health. It is important to recognize that persons with combined disabilities are at increased risk of cardiovascular and AC mortality.
Karpa
Michael J
MJ
Centre for Vision Research, Department of Ophthalmology, Westmead Millennium Institute, University of Sydney, Sydney, Australia.
Gopinath
Bamini
B
Beath
Ken
K
Rochtchina
Elena
E
Cumming
Robert G
RG
Wang
Jie Jin
JJ
Mitchell
Paul
P
D000367:Age Factors; D000368:Aged; D001315:Australia / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000401:mortality*; D016001:Confidence Intervals; D005260:Female; D006306:Health Surveys; D034381:Hearing Loss / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors