Association between Anemia and Auditory Threshold Shifts in the US Population: National Health and Nutrition Examination Survey

Hypothesis Tests for Continuous Audiometric Threshold Data

OBJECTIVES

Hypothesis tests for hearing threshold data may be challenging due to the special structure of the response variable, which consists of the measurements from the participant's two ears at multiple frequencies. The commonly-used methods may have inflated type I error rates for the global test that examines whether exposure-hearing threshold associations exist in at least one of the frequencies. We propose using both-ear methods, including all frequencies in the same model for hypothesis testing.

DESIGN

We compared the both-ear method to commonly used single-ear methods, such as the worse-ear, better-ear, left/right-ear, average-ear methods, and both-ear methods that evaluate individual audiometric frequencies in separate models, through both theoretical consideration and a simulation study. Differences between the methods were illustrated using hypothesis tests for the associations between the Dietary Approaches to Stop Hypertension adherence score and 3-year change in hearing thresholds among participants in the Conservation of Hearing Study.

RESULTS

We found that (1) in the absence of ear-level confounders, the better-ear, worse-ear and left/right-ear methods have less power for frequency-specific tests and for the global test; (2) in the presence of ear-level confounders, the better-ear and worse-ear methods are invalid, and the left/right-ear and average-ear methods have less power, with the power loss in the left/right-ear much greater than the average-ear method, for frequency-specific tests and for the global test; and (3) the both-ear method with separate analyses for individual frequencies is invalid for the global test.

CONCLUSIONS

For hypothesis testing to evaluate whether there are significant associations between an exposure of interest and audiometric hearing threshold measurements, the both-ear method that includes all frequencies in the same model is the recommended analytic approach.

The Association between Dietary Intakes of Vitamins and Minerals with Tinnitus

BACKGROUND

Tinnitus is the phantom perception of sound in the ears or head which may result from inflammation of the auditory pathway. A healthy diet consisting of a range of vitamins and minerals may be protective against tinnitus. This study aims to determine the association between intakes of dietary vitamins and minerals and the prevalence and incidence of tinnitus over 10 years.

METHODS

In this longitudinal cohort study of 2947 participants (aged ≥ 50 years), 935 (32%) cases of tinnitus were identified and included in prevalence analyses. The remaining 2012 participants were followed to establish 10-year incidence of tinnitus. A validated semi-quantitative food frequency questionnaire was used to determine intakes of dietary vitamins and minerals.

RESULTS

No significant associations with tinnitus prevalence were found. However, iron and zinc were significantly associated with incident tinnitus. There was a 44% (multivariate-adjusted HR: 1.44, 95% CI: 1.07-1.93) increased risk of developing incident tinnitus over 10 years with lower zinc intakes and a 35% increased risk with lower iron intakes (multivariate-adjusted HR: 1.35, 95% CI: 1.00-1.80).

CONCLUSION

Higher intakes of zinc and iron were significantly associated with lower tinnitus risk. Due to a lack of comparable high-quality data, future research studies should include robust study designs.

Illegal Drug Use and Risk of Hearing Loss in the United States: A National Health and Nutrition Examination Survey

The use of illegal drugs may be a risk factor of hearing loss. However, very few studies with large sample size have investigated the relationship between illegal drug use and hearing loss. Therefore, to evaluate the association between illegal drug use and hearing loss, this cross-sectional population-based study collected data from the US National Health and Nutrition Examination Survey 2011. The study included 1772 participants aged 20 to 59 years who underwent the Drug Use Questionnaire and Audiometry Examination. Of the 1772 participants in this study, 865 were men (48.8%) and 497 were illegal drug users. The mean (SD) age of the patients was 40.0 (11.4) years. After considering age, sex, and comorbidities, the participants who used illegal drugs were found to have higher risks of high-frequency hearing loss (adjusted odds ratio (OR), 1.69; 95% confidence interval (CI), 1.35–2.10) and overall hearing loss (adjusted OR, 1.69; 95% CI, 1.36–2.12) as compared with the nonusers. In the second analysis, the participants who used ≥ 2 types of illegal drugs were associated with higher risks of high-frequency hearing loss (adjusted OR, 1.57; 95% CI, 1.06–2.32) and overall hearing loss (adjusted OR, 1.60; 95% CI, 1.08–2.37). In the third analysis, cocaine use was associated with increased risks of high-frequency hearing loss (adjusted OR, 1.34; 95% CI, 1.01–1.77) and overall hearing loss (adjusted OR, 1.38; 95% CI, 1.04–1.82). The adjusted OR for overall hearing loss in the methamphetamine users was 1.54 (95% CI, 1.05–2.27) as compared with that in the nonusers. This study shows that illegal drug users might have a higher risk of overall hearing loss than nonusers. In addition, the analysis results demonstrated that the more kinds of illegal drugs used, the higher the risk of hearing loss. Further experimental and longitudinal research studies are required to confirm the causal relationship between illegal drug use and hearing loss.

Topic Modeling for Analyzing Patients' Perceptions and Concerns of Hearing Loss on Social Q&A Sites: Incorporating Patients' Perspective

Hearing loss is the most common human sensory deficit, affecting normal communication. Recently, patients with hearing loss or at risk of hearing loss are increasingly turning to the online health community for health information and support. Information on health-related topics exchanged on the Internet is a useful resource to examine patients' informational needs. The ability to understand the patients' perspectives on hearing loss is critical for health professionals to develop a patient-centered intervention. In this paper, we apply Latent Dirichlet Allocation (LDA) on electronic patient-authored questions on social question-and-answer (Q&A) sites to identify patients' perceptions, concerns, and needs on hearing loss. Our results reveal 21 topics, which are both representative and meaningful, and mostly correspond to sub-fields established in hearing science research. The latent topics are classified into five themes, which include "sudden hearing loss", "tinnitus", "noise-induced hearing loss", "hearing aids", "dizziness", "curiosity about hearing loss", "otitis media" and "complications of disease". Our topic analysis of patients' questions on the topic of hearing loss allows achieving a thorough understanding of patients' perspectives, thereby leading to better development of the patient-centered intervention.