Five-Year Incidence and Progression of Hearing Impairment in an Older Population Paul Mitchell, 1 Bamini Gopinath, 1,2 Jie Jin Wang, 1,3 Catherine M. McMahon, 4 Julie Schneider, 2 Elena Rochtchina, 1 and Stephen R. Leeder 2 Objectives: There are few epidemiological surveys that have examined age-related hearing loss in an older Australian population. This study reports the prevalence, 5-yr incidence, and progression of hearing impairment in a representative sample of older persons. Design: The Blue Mountains Hearing Study (BMHS) is a population- based survey of age-related hearing loss conducted among participants of the Blue Mountains Eye Study cohort. During the period 1997–1999, 2956 had audiometric testing done. Of these, 870 participants without hearing loss and 439 with hearing loss were re-examined from 2002 to 2004. Results: Some degree of hearing loss was present in 33.0% of this population at baseline. Prevalence of hearing loss increased with age, sex-adjusted (odds ratio [OR] 3.5, 95% confidence interval [CI] 3.1– 3.9), with men 70% more likely than women to have hearing loss. The 5-yr incidence of hearing impairment was 17.9%. For each decade of age older than 60 yrs, the risk of hearing loss increased threefold, OR 3.9 (CI 2.3–3.8). Gender was not associated with incident hearing loss OR. However, high occupational prestige was associated with decreased incidence of hearing loss OR 0.6 (CI 0.40 – 0.94). The 5-yr progression of hearing loss defined as a difference in pure-tone average that exceeded 10 dB was relatively high (15.7%). At the baseline hearing study and at the 5-yr follow-up hearing study, 57.4% and 59.7% of hearing impaired subjects, respectively, reported using a hearing aid for a maximum of 5 yrs. Conclusions: Hearing loss was a frequent sensory disability, with one in three persons having a hearing impairment, and of these, almost one in two showing a decline in hearing over a 5-yr period. This information can potentially contribute to the planning and resource investment in auditory rehabilitation services for older Australians. (Ear & Hearing 2011;32;251–257) INTRODUCTION Hearing impairment is one of the most frequent disabilities (Cruickshanks et al. 1998; Wilson et al. 1999). Sensorineural age-related hearing loss is the most common form of hearing impairment (Gratton & Vasquez 2003), with reported preva- lence between 30% and 46% of older population-based sam- ples (Gates et al. 1990; Cruickshanks et al. 1998; Gopinath et al. 2009). The U.S. Epidemiology of Hearing Loss Study (EHLS) (Cruickshanks et al. 1998) reported a 90% prevalence of measured hearing loss among persons aged 80 yrs or older. Despite its frequency, only a few studies have examined the incidence and longitudinal course of hearing loss in represen- tative population samples, and very few surveys have focused on incident hearing loss in older adults (Gates & Cooper 1991; Pearson et al. 1995; Brant et al. 1996; Cruickshanks et al. 2003; Hietanen et al. 2004). In the Framingham study (Gates & Cooper 1991), 13.7% of participants aged 57 to 89 yrs developed a hearing impairment in the left ear over a 6-yr period. In the Baltimore Longitudinal Study of Aging (Pearson et al. 1995), 17% of men aged 70 yrs or older at baseline developed hearing loss over 5 to 8 yrs. In the follow-up EHLS (Cruickshanks et al. 2003), the 5-yr incidence of hearing impairment was 21% among individuals initially aged 48 to 92 yrs. However, these cohort studies have some caveats that require highlighting. First, the Framingham (Gates & Cooper 1991) and Baltimore (Pearson et al. 1995) studies may have underestimated incident age-related hearing loss as they did not include participants with a history of cardiovascular disease or noise exposure, respectively (Cruick- shanks et al. 2003). Second, although the EHLS did include participants with a history of cardiovascular disease and noise exposure, this study assessed hearing loss in the worse ear. This definition of worse ear is not in convention with most previous studies (Gates et al. 1990; Moscicki et al. 1999). Hence, in this study, we will seek to address the gaps of these previously published studies to provide an accurate estimate of incident age-related hearing loss in older adults. Population-based data on the course of measured hearing loss in older adults are needed to identify its extent, level, and impact. These data are also important to develop policy and plan and implement hearing-related health care services. The current report presents data from the largest cohort study to simultaneously examine the prevalence, 5-yr incidence, and progression of bilateral hearing loss in a representative sample of older Australians living in a defined population west of Sydney, Australia. SUBJECTS AND METHODS Study Population The Blue Mountains Hearing Study (BMHS) (Gopinath et al. 2009, 2010) is a population-based survey of age-related hearing loss conducted during the years 1997–2004 among participants of the Blue Mountains Eye Study (BMES) cohort (Attebo et al. 1996). During 1992–1994, 3654 participants aged 49 yrs or older were examined (82.4% participation; BMES-1). Surviving baseline participants were invited to attend 5-yr (1997–1999, BMES-2) and 10-yr (2002– 4, BMES-3) fol- low-up examinations, in which 2334 (75.1% of survivors) and 1952 participants (75.6% of survivors) were re-examined, respectively. Figure 1 shows the distribution of participation in hearing studies that were performed between 1997–1999 and 2002–2004 in the Blue Mountains cohort. 1 Centre for Vision Research, Department of Ophthalmology and Westmead Millennium Institute, University of Sydney; 2 Menzies Centre for Health Policy, University of Sydney, Sydney, New South Wales; 3 Centre for Eye Research Australia, Department of Ophthalmology, University of Mel- bourne, Melbourne, Victoria; 4 Centre for Language Sciences, Linguistics Department, Macquarie University, Sydney, New South Wales, Australia. 0196/0202/11/3202-0251/0 • Ear & Hearing • Copyright © 2011 by Lippincott Williams & Wilkins • Printed in the U.S.A. 251