The NHIS is an annual, continuous, multi-purpose, and multistage probability cross-sectional survey of the US civilian noninstitutionalized population and is conducted by the National Center for Health Statistics.12^,13 A probability sample of households is selected with family members interviewed by trained personnel; 1 adult from each household is selected at random and administered a health-oriented questionnaire (i.e., “the adult core”), which includes questions about HI and VI. Annual response rates to the 1997 to 2002 adult core ranged from 70% (in 1999) to 80% (in 1997).14^–19 More than 195000 adult participants of the 1997 to 2002 NHIS were administered the following questions: (1) “Do you have any trouble seeing, even when wearing glasses or contact lenses?”; (2) “Are you blind or unable to see at all?”; and (3) “Which statement best describes your hearing (without a hearing aid): good, a little trouble, a lot of trouble, deaf.” Participants responding yes to either of the first 2 questions were considered to be visually impaired. Participants reporting a little trouble, a lot of trouble, or that they were deaf were classified as hearing impaired.

Analyses were completed using the Software for the Statistical Analysis of Correlated Data (Research Triangle Institute, Research Triangle Park, NC) package to take into account sample weights and design effects.20 Sample weights were adjusted to account for the aggregation of data over multiple survey years.21 Subgroup prevalence rates were compared using approximate Z tests; trend analyses were used for age-group-specific rates. When comparing more than 2 groups, P values were adjusted using Bonferroni’s approach for multiple comparisons. Age-adjusted rates of VI only, HI only, and HI+VI were calculated by the direct method using the 2000 US Census population as the standard.22

Overall prevalence rates of HI only were approximately twice as those of VI only (Table 1 , 13.1 vs 6.0). The overall prevalence of HI+VI was 3.3% and increased from 1.3% for participants aged 18–44 years to 16.6% for participants aged 80 years or older (P for trend <.01). Age-adjusted rates of HI+VI were slightly but significantly higher in men versus women (3.6% vs 3.2%; P<.001), in adults with less than a 12th grade education versus adults with more than a 12th grade education (4.9% vs 2.8%; P<0.001), and in nonmarried versus married adults (4.1% vs 2.9%; P<.001). Aleut, Eskimo, and American Indians reported more than 3 times the rate of HI+VI relative to Asian/Pacific Islander Americans (6.3% vs 1.8%; P<.001); rates for Aleut, Eskimo, and American Indians were also significantly greater than for any of the other race groups (all P values <.01).

TABLE 1— Prevalence (%) of Hearing Impairment Only, and Visual Impairment Only, and Concurrent Hearing and Visual Impairment by Different Subgroups, Among 1997–2002 National Health Interview Survey Participants 18 Years of Age and Older

The NHIS is limited by the self-reported nature of hearing and vision impairment ascertainment. However, the sensitivity and specificity of self-reported measures of HI range from 56% to 93% and 56% to 82%, respectively, when using pure tone audiometric findings as the “gold standard.”23 Overall VI assessed by either 1 or 2 items within the National Eye Institute Visual Function Questionnaire is significantly correlated with clinically assessed visual acuity (range of correlations, 0.65–0.68).24^,25 Nonresponse to the “adult core” interview where impairment questions were administered represents another possible study limitation because of the potential biasing effects of systematic nonresponse.

More than 16% of adults aged 80 years or older report HI+VI, and census projections indicate that the size of this segment of the US population will increase 25% in the next 15 years.26 Therefore, these impairments will pose important challenges for increasing numbers of families and family caregivers in the coming years.27 The correction of visual and hearing deficits improves quality of life and is associated with reduced risk of mortality,2^,28^,29 yet routine coverage for many of these services is not provided by Medicare (e.g., corrective lenses and hearing aids). Policymakers should vigorously pursue expansion of such coverage.

Finally, it is unknown why Aleut, Eskimo, and Native Americans have significantly higher rates of HI+VI, but this may be because of limited health care access,30 possibly in combination with increased risks of auditory disorders31^–33 and angle closure glaucoma.34^,35 Additional research in this race group is clearly warranted given the paucity of studies on these impairments in this diverse and understudied race group.36^–38

This study was supported in part by the National Institute on Aging (grant R01 AG021627).

The data used in this publication were made available in part by the Inter-University Consortium for Political and Social Research. The data for the National Health Interview Survey were originally collected and prepared by the US Department of Health and Human Services and the National Center for Health Statistics. Neither the collector of the original data nor the Consortium bears any responsibility for the analyses or interpretations presented in this publication.

Human Participant Protection
The protocol was reviewed and approved for exemption by the institutional review board of the University of Miami, Miller School of Medicine, because this study uses anonymous data from a publicly available database.