1. Ten-year Incidence of Hearing Impairment in Beaver Dam, WI
KJ Cruickshanks, DM Nondahl,
BEK Klein, R Klein, TL Wiley, TS Tweed
University of Wisconsin
School of Medicine and Public Health
NIH-R01 AG11099 & U10 EY06594

2. Background
Few data on the incidence of hearing impairment in older adults:
Framingham:
6-yr incidence: 13.7% (l) and 8.4% (r)
BLSA:
Men age 70+ yrs: 17%; mean 5 yr follow-up
Men age yrs: 13%; mean 7.8 yr follow-up
EHLS:
5-yr incidence: 21%
Gates GA, Acta Otolaryngol 1991; 111: ;
Brandt LJ, J Am Acad Audiol 1996;7: ;
Cruickshanks KJ, Arch Otolaryngol Head Neck Surg 2003;129:

3. Purpose
To determine the long-term risk of developing hearing impairment in a population-based study of older adults

4. Beaver Dam, WI

5. Epidemiology of Hearing Loss Study (1993-2008+)
Residents of Beaver Dam in 1987
Ages yrs in 1987
Participated in the Beaver Dam Eye Study in (n=4926; 83%)
Alive in 1993 (n=4541)

6. Overall Participation by time here

7. Data Otoscopy Screening tympanometry Audiometry DPOAE
Self-reported hearing handicap (HHIE-S)
Questionnaire data - Lifestyle, medical history, occupation, etc.
Laboratory measures (GHb; Cholesterol and HDL-C (B, 5yrs))
Medications
SDOIT, MMSE, IMT added after baseline

8. Audiometry Pure tone air and bone conduction 500-8000 Hz (air)
500, 2000, 4000 Hz (bone)
Masking as needed
TDH-50 earphones or E-A-Rtone 3A inserts
Virtual 320, GSI-60, Beltone 112

9. Occupation and noise histories
Longest held full-time job
Noise history
Full-time job – speak in raised voice or louder to be heard (2 ft) and/or
Farmer (tractor without a cab) and/or
Military service: pilot; aircraft or tracked vehicle crewmember; worked in engine room; operated multi-person weapons systems; used grenades, mortars, shoulder-held launchers; or spent time on weapons ranges 7 or more times per year

10. Quality Assurance Calibration every 6 months Listening checks
Examiner variability monitored
Ambient sound levels monitored

11. Definitions Hearing Impairment PTA at 0.5,1,2,4 kHz > 25 dB HL
10-yr Cumulative Incidence
Impairment at a follow-up examination among those with no impairment at baseline

12. Analytic Methods Kaplan-Meier (Product-limit) Method
Cox Proportional Hazard Models

13. Participation for incidence study

14. Baseline Characteristics (1993-95): Participants (n=1925) at risk for hearing impairment
Mean Age (SD)
61.0 (8.5)
Men
33.1%
Positive Noise History
50.8%
Professional Occupation
23.7%
16+ Years Education
18.9%
Mean PTA (SD)
14.8 (6.1)

15. 10-yr Cumulative Incidence of Hearing Impairment by Age and Gender: The Epidemiology of Hearing Loss Study, Beaver Dam, WI
37.2%

16. Mean Baseline PTA by 10-yr Incident Case Status: The Epidemiology of Hearing Loss Study, Beaver Dam, WI

17. Mean Baseline Hearing Thresholds (dB HL) by Incident Case Status: The Epidemiology of Hearing Loss Study, Beaver Dam, WI

18. 10-yr Cumulative Incidence of Hearing Impairment by Occupation: The Epidemiology of Hearing Loss Study, Beaver Dam, WI

19. 10-yr Cumulative Incidence of Hearing Impairment by Education: The Epidemiology of Hearing Loss Study, Beaver Dam, WI

20. 10-yr Cumulative Incidence of Hearing Impairment by Noise History: The Epidemiology of Hearing Loss Study, Beaver Dam, WI

21. Hazard Model for Incidence of Hearing Impairment
2.36
1.76
1.51
1.60
1.83
------Years of school (vs 16+)------

22. Conclusions
Older adults have a high risk of developing hearing impairment
Age, gender, and education but not occupation or noise history are independent predictors of risk
The gender gap was not explained by work or noise and remained until the oldest age group
The education effect suggests that other lifestyle or health factors may be important in the etiology of hearing impairment