Hearing Impairment in 2008: A compilation of available epidemiological studies

Auditory Steady-State Response and Hearing Impairment in Survivors of Childhood Bacterial Meningitis in Luanda, Angola

Survivors of childhood bacterial meningitis (BM) often develop hearing impairment (HI). In low- and middle-income countries (LMICs), BM continues to be a significant cause of hearing disability. We assessed hearing among BM survivors using auditory steady-state responses (ASSR), providing frequency-specific estimated audiograms, and examined whether ASSR would provide a greater understanding of BM-induced HI. Survivors from two prospective BM trials (ISRCTN62824827; NCT01540838) from Luanda Children's Hospital were examined in a follow-up visit with a median duration of 26 months after BM. The hearing of 50 BM survivors and 19 control children was evaluated using ASSR and auditory brainstem response (ABR) after interview and neurological and otorhinolaryngological examinations. The median age of survivors was 80 (IQR 86) months. We diagnosed HI (better ear hearing ≥ 26 dB) in 9/50 (18%) children. Five of the fifty survivors (10%) and 14/100 ears (14%) had profound HI (>80 dB). Severe-to-profound HI affected all frequencies steadily, affecting only the ears of BM survivors (18/100 vs. 0/38, p = 0.003). When looking only at the severely or profoundly affected ears, young age, low Glascow coma score, pneumococcal aetiology, and ataxia were associated with a worse hearing outcome.

Forty years on: a new national study of hearing in England and implications for global hearing health policy

OBJECTIVE

We aimed to update the prevalence estimates of hearing loss in older adults in England using a nationally representative sample of adults aged 50 years old and older.

DESIGN

A comparative cross-sectional study design was implemented. Hearing loss was defined as ≥35 dB HL at 3.0 kHz, as measured via Hearcheck in the better-hearing ear.

STUDY SAMPLE

We compared the estimates based on the English census in 2015 to estimates from psychoacoustic hearing data available for 8,263 participants in the English Longitudinal Study of Ageing (ELSA) Wave 7 (2014-2015).

RESULTS

Marked regional variability in hearing loss prevalence was revealed among participants with similar age profiles. The regional differences in hearing outcomes reached up to 13.53% in those belonging to the 71-80 years old group; the prevalence of hearing loss was 49.22% in the North East of England (95%CI 48.0-50.4), versus 35.69% in the South East (95%CI 34.8-36.50).

CONCLUSION

A socio-spatial approach in planning sustainable models of hearing care based on the actual populations' needs and not on age demographics might offer a viable opportunity for healthier lives. Regular assessment of the extent and causality of the population's different audiological needs within the country is strongly supported.

National Infant Screening for Hearing Program in India: Necessity, Significance and Justification

Hearing impairment is one of the most prevalent disorder in children and adults worldwide, which not only interferes with the acquisition, development and maintenance of speech and language skills but also adversely deprive the auditory nervous system for future learning. It can have long term harmful effect on educational, social, emotional and cognitive skills in young children; restrict the vocational options and employment opportunities in adults; and can cause isolation, loneliness and depression in older adults, if remain undetected and intervened at the earliest. However, early identification and intervention is known to greatly reverse the ill effects and improve the quality of life of children and adults with hearing impairment. Current clinical means and methods to identify and intervene hearing loss are convenient, cost effective, reasonably accurate beneficial and evidenced based, can be easily employed nation-wide for early identification and intervention of hearing loss. This paper attempts to convince medical colleagues, public health care experts and policy makers by justifying the hearing, as public health issue and relevance of medical screening criteria for hearing. It also discusses the preferred model of hearing screening and intervention strategies in India.

Implementation of National Infant Screening for Hearing Program in India: Challenges, Opportunities and Suggested Framework

Hearing impairment is most frequent sensory deficit present in infants at birth and unaddressed hearing impairment causes severe damages to both infants and their families. In India 77,756 live children are born per day which accounts for about 25 million children annually among them approximately 1.5 lacs (@ 6 per1000) children born with hearing impairment. These children have no prospects of early identification & intervention. As a result, majority of these children suffers from oral communication difficulties, poor academic performance, reduced psychosocial & cognitive development, socioeconomic insufficiency, deprived vocational opportunities & employability. However, consequences of hearing impairment are ameliorable if timely hearing screening and effective intervention strategies are instituted. Unfortunately, India has not yet envisaged any dedicated early identification and intervention program for children with hearing impairment. However, there are ample of opportunities for implementing such program. Hence, this paper endeavours to address the necessity to plan and to implement the early identification of hearing impairment by discussing burden of disorder, suggesting means to overcome the challenges and to explore and emphasize the opportunities of purposeful utilization of available infrastructure and resources. This paper also intends to suggest a conceptual framework for planning and implementing of National Infant Screening for Hearing Program to deal with serious consequences of hearing impairment in India.

Prevalence of hearing loss in children living in low- and middle-income countries over the last 10 years: A systematic review

AIM

To summarize the literature on the prevalence of pediatric hearing loss in low- and middle-income countries (LMICs).

METHOD

A systematic review initially identified 2833 studies, of which 122 met the criteria for inclusion. Eighty-six of those studies included diagnoses and were included in a meta-analysis.

RESULTS

The meta-analysis indicated a 1% (95% confidence interval = 0.8-2.0) prevalence of childhood hearing loss across LMICs. There was significant heterogeneity between studies and evidence of publication bias. The prevalence of mild and moderate cases of hearing loss was higher than more severe cases and there were fewer cases of mixed hearing loss compared to conductive or sensorineural hearing loss. No differences were identified between the prevalence of unilateral versus bilateral hearing loss or hearing loss according to sex. The quality of the studies, age of participants, and location of data collection may have influenced the results. High variability in the reporting of etiology made the causes of hearing loss unclear.

INTERPRETATION

The literature indicates that 1% of children in LMICs have hearing losses. However, most studies missed children with acquired hearing loss, which may lead to under-reporting of global prevalence. This systematic review is an initial step toward developing and implementing population-appropriate treatment and prevention programs for childhood hearing loss in LMICs.

Prevalence of Hearing Impairment by Age: 2nd to 10th Decades of Life

Background: Accurate data on the prevalence of hearing impairment and severity across age and gender are paramount to formulate hearing health policies. Here, we sought to analyze audiometric data from a large group of age-diverse people in Japan, which has not been previously described in detail. Methods: We analyzed retrospective hearing threshold data of 23,860 participants (10−99 years; left-right hearing threshold difference <15 dB; air-bone gap ≤10 dB) at 500, 1000, 2000, and 4000 Hz, and then classified them for hearing impairment severity according to the WHO Classification. Findings: There was a significant gender difference in median hearing thresholds, starting in 20-year-olds up to early 80-year-olds. Twenty-five percent of men in their late 50s had some level of HI, ~50% in their late 60s, and ~75% in their late 70s. For women, 25% had some level of HI in their early 60s, ~50% in their early 70s, and ~75% in their late 70s. For participants in their early 80s, 50% of either gender had moderate or more severe HI. Interpretation: Our results, derived from a large number of participants, provide basic information about the prevalence of hearing loss by age decade. Since people can expect to live longer than those in previous generations, our detailed data can inform national social systems responsible for hearing screening in making decisions about hearing-aid qualification, which may reduce barriers to older people’s independence, productivity, and quality of life.

Prevalence of Hearing Loss and Hearing Aid Use Among Adults in France in the CONSTANCES Study

IMPORTANCE

Although hearing loss is common in the population worldwide, the prevalence of hearing loss and hearing aid use is not known.

OBJECTIVE

To estimate the prevalence of hearing loss and hearing aid use in the adult French population.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the CONSTANCES cohort, a representative sample of the French population. Volunteers aged 18 to 75 years were recruited at 21 preventive health centers between January 1, 2012, and December 31, 2019. The present study included participants with audiometric data.

MAIN OUTCOMES AND MEASURES

The main outcomes were prevalence of hearing loss and disabling hearing loss overall and by sex and age group and prevalence of self-reported hearing aid use among those with disabling hearing loss. Hearing loss was defined as a pure-tone average (PTA) in the better ear of 20 dB or higher, and disabling hearing loss was defined as a PTA in the better ear of 35 dB or higher.

RESULTS

Of 200 870 participants in the CONSTANCES study, 186 460 had full audiometric data and were included in this study (mean [SD] age, 47.1 [13.5] years); 100 330 (53.8%) were female, and 86 130 (46.2%) were male. Of these participants, 24.8% (95% CI, 24.6%-25.0%) had hearing loss and 4.3% (95% CI, 4.2%-4.4%) had disabling hearing loss. The prevalence rates of hearing loss increased from 3.4% (95% CI, 2.8%-3.9%) at age 18 to 25 years to 73.3% (95% CI, 69.5%-77.2%) at age 71 to 75 years among men and from 4.4% (95% CI, 3.9%-5.0%) at age 18 to 25 years to 64.1% (95% CI, 59.7%-68.4%) at age 71 to 75 years among women. The prevalence of disabling hearing loss increased from 0.3% (95% CI, 0.2%-0.4%) among participants aged 18 to 25 years to 23.3% (95% CI, 20.7%-26.0%) among participants aged 71 to 75 years. Among the 8050 participants with disabling hearing loss, 36.8% (95% CI, 35.8%-37.9%) reported using hearing aids, including 56.7% (95% CI, 38.9%-74.4%) aged 18 to 25 years and 32.9% (95% CI, 26.8%-39.2%) aged 71 to 75 years.

CONCLUSIONS AND RELEVANCE

In this cohort study, hearing loss was prevalent in France, and the prevalence of hearing loss increased with age among both men and women. Hearing aids were underused, particularly among older individuals. These findings suggest that hearing loss prevention and screening in the French population are needed.

Hearing Loss and Its Burden of Disease in a Large German Cohort-Hearing Loss in Germany

OBJECTIVES/HYPOTHESIS

Hearing loss is the most common sensory impairment worldwide. It restricts patients in many aspects of their daily lives and can lead to social exclusion. Understanding this burden is a mandatory requirement for the care of those affected. Therefore, the aim of this study was to estimate the burden of hearing loss in a large German cohort.

STUDY DESIGN

Cohort study.

METHODS

The Gutenberg Health Study is designed as a single-center, prospective, and observational cohort study and representative for the city of Mainz, Germany, with its district. Participants were interviewed concerning common otologic symptoms and tested by pure-tone audiometry. The primary outcome was hearing impairment stratified by age and sex. The prevalence of tinnitus was estimated for a subcohort to calculate disability-adjusted life years (DALYs). All results were weighted by the European Standard Population (ESP) 2013.

RESULTS

A total of 5,024 participants (mean age: 61.2 years, 2,591 men and 2,433 women) were included in the study. Hearing impairment showed the following prevalence: 28.2% (95% confidence interval [CI], 26.9%-29.4%) mild impairment, 10.1% (95% CI, 9.3%-11.0%) moderate impairment, 2.3% (95% CI, 1.9%-2.7%) moderately severe impairment, 0.2% (95% CI, 0.1%-0.4%) severe impairment, 0% (95% CI, 0.0%-0.1%) profound impairment, and 0.1% (95% CI, 0.0%-0.2%) complete impairment. Weighted for the ESP 2013 (all ages), hearing impairment across all levels (with/without tinnitus) causes a total of 2,118.97 DALYs per 100,000.

CONCLUSION

With 40.9% affected, the hearing loss represents a relevant burden of the German population. Understanding this will provide the basis for future guidelines on how to care for these patients.

LEVEL OF EVIDENCE

2 Laryngoscope, 2021.

A Study on the Relationship between Cognitive Performance, Hearing Impairment, and Frailty in Older Adults

INTRODUCTION

As the human lifespan rises, older people are increasingly affected by multimorbidity, including hearing impairment (HI), frailty, and cognitive decline.

OBJECTIVE

We studied the effect of HI on the cognitive performance of older patients with mild cognitive impairment and mild dementia and how this effect is altered when HI and frailty coexist.

METHODS

The sample comprised 172 outpatients (age ≥65 years) with a Clinical Dementia Rating of 0.5-1 and a Mini-Mental State Examination score ≥20. Cognitive, neuropsychological, physical function tests, and body measurements were performed. The participants' comorbidity indices were calculated, and they were asked to report their hearing condition. Finally, the participants were divided into 4 groups based on the presence of frailty, HI, both conditions, or neither.

RESULTS

The presence of HI was significantly associated with a lower Digit Symbol Substitution Test (DSST) score (unadjusted model: p = 0.003; adjusted: p = 0.012). Moreover, people with both HI and frailty were more likely to have a low DSST score than those in the other groups (unadjusted model: OR: 3.741, 95% CI: 1.374-10.183, p = 0.010; adjusted model: OR: 4.192, 95% CI: 1.026-17.136, p = 0.046).

CONCLUSIONS

This study highlights the negative relationship between cognitive performance scored on the DSST and the presence of HI. Furthermore, the presence of both frailty and HI is associated with a worse cognitive score than HI alone.

Hearing loss prevalence and years lived with disability, 1990-2019: findings from the Global Burden of Disease Study 2019

BACKGROUND

Hearing loss affects access to spoken language, which can affect cognition and development, and can negatively affect social wellbeing. We present updated estimates from the Global Burden of Disease (GBD) study on the prevalence of hearing loss in 2019, as well as the condition's associated disability.

METHODS

We did systematic reviews of population-representative surveys on hearing loss prevalence from 1990 to 2019. We fitted nested meta-regression models for severity-specific prevalence, accounting for hearing aid coverage, cause, and the presence of tinnitus. We also forecasted the prevalence of hearing loss until 2050.

FINDINGS

An estimated 1·57 billion (95% uncertainty interval 1·51-1·64) people globally had hearing loss in 2019, accounting for one in five people (20·3% [19·5-21·1]). Of these, 403·3 million (357·3-449·5) people had hearing loss that was moderate or higher in severity after adjusting for hearing aid use, and 430·4 million (381·7-479·6) without adjustment. The largest number of people with moderate-to-complete hearing loss resided in the Western Pacific region (127·1 million people [112·3-142·6]). Of all people with a hearing impairment, 62·1% (60·2-63·9) were older than 50 years. The Healthcare Access and Quality (HAQ) Index explained 65·8% of the variation in national age-standardised rates of years lived with disability, because countries with a low HAQ Index had higher rates of years lived with disability. By 2050, a projected 2·45 billion (2·35-2·56) people will have hearing loss, a 56·1% (47·3-65·2) increase from 2019, despite stable age-standardised prevalence.

INTERPRETATION

As populations age, the number of people with hearing loss will increase. Interventions such as childhood screening, hearing aids, effective management of otitis media and meningitis, and cochlear implants have the potential to ameliorate this burden. Because the burden of moderate-to-complete hearing loss is concentrated in countries with low health-care quality and access, stronger health-care provision mechanisms are needed to reduce the burden of unaddressed hearing loss in these settings.

FUNDING

Bill & Melinda Gates Foundation and WHO.

A new approach to estimating the prevalence of hereditary hearing loss: An analysis of the distribution of sign language users based on census data in Russia

The absence of comparable epidemiological data challenges the correct estimation of the prevalence of congenital hearing loss (HL) around the world. Sign language (SL) is known as the main type of communication of deaf people. We suggest that the distribution of SL can be interpreted as an indirect indicator of the prevalence of congenital HL. Since a significant part of congenital HL is due to genetic causes, an assessment of the distribution of SL users can reveal regions with an extensive accumulation of hereditary HL. For the first time, we analyzed the data on the distribution of SL users that became available for the total population of Russia by the 2010 census. Seventy-three out of 85 federal regions of Russia were ranked into three groups by the 25th and 75th percentiles of the proportion of SL users: 14 regions-"low proportion"; 48 regions-"average proportion"; and 11 regions-"high proportion". We consider that the observed uneven prevalence of SL users can reflect underlying hereditary forms of congenital HL accumulated in certain populations by specific genetic background and population structure. At least, the data from this study indicate that the highest proportions of SL users detected in some Siberian regions are consistent with the reported accumulation of specific hereditary HL forms in indigenous Yakut, Tuvinian and Altaian populations.

Assessment and Modeling of the Influence of Age, Gender, and Family History of Hearing Problems on the Probability of Suffering Hearing Loss in the Working Population

Hearing loss affects hundreds of millions of people all over the world, leading to several types of disabilities, ranging from purely physical to psychological and/or social aspects. A proper analysis to ascertain the main risk factors is essential in order to diagnose early and treat adequately. An exploratory analysis based on a heterogeneous sample of 1418 workers is presented in order to identify the main trigger factors for hearing loss. On the one hand, we recorded several medical and environmental parameters, and on the other, we created a model based on Bayesian networks in order to be able to infer the probability of hearing loss considering different scenarios. This paper focuses on three parameters: gender, age, and a family history of hearing problems. The results obtained allow us to infer or predict the best or worst auditory level for an individual under several different scenarios. The least relevant factor is the existence of a family history of deafness, followed by the gender factor, which slopes considerably toward better hearing for females, and most prominent of all, the age factor, given the large differences identified between the various age groups when the gender and family history of deafness variables remain constant.

Discussing Hearing Aid Rehabilitation at the Hearing Clinic: Patient Involvement in Deciding upon the Need for a Hearing Aid

The quality of interaction between hearing health professionals and patients is one prominent, yet under-studied explanation for the low adherence in acquiring and using a hearing aid. This study describes two different ways of introducing hearing aid to the patients at their first visits at the hearing clinic: an inquiry asking patients opinion followed by offer, and an expert evaluation of the necessity of a hearing aid; and shows two different trajectories ensuing from these introductions. The trajectories represent two extreme ends of a continuum of practices of starting a discussion about hearing aid rehabilitation, in terms of how these practices affect patient participation in decision-making. The analysis shows how granting different degrees of deontic and epistemic rights to professionals and patients has different consequences with regard to the activity of reaching shared understanding on the treatment. The data consist of 17 video-recorded encounters at the hearing clinic. The method used is conversation analysis.

A National Survey of Hearing Loss in the Philippines

This study aimed to estimate the prevalence of hearing loss in the Philippines using a nationally representative sample. A cross-sectional national survey was undertaken utilizing a 3-stage stratified cluster design. Participants in the present study comprised 2275 adults and children with pure tone hearing assessment results. Prevalence of moderate or worse hearing loss, defined as 4FA ≥41 dBHL, was 7.5% in children <18 years, 14.7% in adults between 18 and 65 years, and 49.1% in adults >65 years. Factors associated with greater risk of moderate hearing loss in the better ear were presence of a middle ear condition (adjusted odds ratio = 2.39, 95% confidence interval = 1.49-3.85) and socioeconomic status (household income; adjusted odds ratio = 1.64, 95% confidence interval = 1.23-2.19). Age was also associated with increased risk, with adjusted odds ratios varying with age category. Prevalence of wax occlusion and outer and middle ear disease was 12.2% and 14.2%, respectively. Prevalence of hearing loss, outer, and middle ear disease appear comparatively high in the Philippines when compared with rates reported in high-income countries. Higher proportions of severe to profound hearing loss were also identified, indicating that there is both an increased prevalence and severity of hearing loss in this population.

Field test of the Rapid Assessment of Hearing Loss survey protocol in Ntcheu district, Malawi

Objective: (1) To test the feasibility of the Rapid Assessment of Hearing Loss (RAHL) survey protocol in Malawi (Ntcheu); (2) To estimate the prevalence and probable causes of hearing loss (adults 50+).Design: Cross-sectional population-based survey.Study sample: Clusters (n = 38) were selected using probability-proportionate-to-size-sampling. Within each cluster, 30 people aged 50+ were selected using compact-segment-sampling. All participants completed smartphone-based audiometry (hearTest). Prevalence was estimated using WHO definitions (PTA of thresholds 0.5, 1, 2, 4 kHz in the better ear of >25 dB HL (any) and >40 dB HL (≥moderate)). Otoscopy and questionnaire were used to assess probable causes. Participants with hearing loss and/or ear disease were asked about care-seeking and barriers.Results: Four teams completed the survey in 24 days. 1080 of 1153 (93.7%) participants were examined. The median time to complete the protocol was 24 min/participant. Prevalence of hearing loss was 35.9% (95% CI = 31.6-40.2) (any level); and 10.0% (95% CI = 7.9-12.5) (≥moderate). The majority was classified as probable sensorineural. Nearly one third of people (30.9%) needed diagnostic audiology services and possible hearing aid fitting. Hearing aid coverage was <1%. Lack of perceived need was a key barrier.Conclusion: The RAHL is simple, fast and provides information about the magnitude and probable causes of hearing loss to plan services.

Evidence for an Association Between Hearing Impairment and Disrupted Sleep: Scoping Review

Purpose Hearing impairment (HI) is the most common sensory impairment and may negatively impact sleep through reduced auditory input. Factors associated with HI such as anxiety regarding communication in daily life may also adversely impact an individual's sleep. Here, research on the relationship between HI and sleep disruption was catalogued using scoping review methodology. Method A systematic strategy was employed to search various electronic databases. This review is reported according to the Preferred Reporting Items for Systematic Review and Meta-Analyses Scoping Review Extension. Results Sixteen records met inclusion criteria. Studies have investigated sleep in HI as a primary aim in noise-exposed workers or large surveys in older participants. Experimental and quasi-experimental studies report alterations to sleep architecture of potential neuroplastic origins. Studies reporting sleep as a secondary aim generally report poorer sleep in HI participants. Conclusions This scoping review has catalogued evidence that altered or negatively impacted sleep may be associated with HI. Potential confounding factors, mechanisms, and considerations for future research are discussed. Supplemental Material https://doi.org/10.23641/asha.9968369.

Mitochondrial DNA mutation m.3243A>G is associated with altered mitochondrial function in peripheral blood mononuclear cells, with heteroplasmy levels and with clinical phenotypes

AIMS

To investigate the associations among heteroplasmy levels (i.e. the proportions of mutant and wild-type mitochondrial DNA in the same cell), mitochondrial function and clinical severity of the m.3243A>G mutation.

METHODS

A total of 17 participants carrying the m.3243A>G mutation and 17 sex- and age-matched healthy controls were included in this study. Heteroplasmy levels of the m.3243A>G mutation in leukocytes, saliva and urine sediment were determined by pyrosequencing. The clinical evaluation included endocrinological, audiological and ophthalmological examinations. Mitochondrial function was determined in peripheral blood mononuclear cells isolated from participants.

RESULTS

Heteroplasmy levels in urine sediment were higher than those in leukocytes and saliva. Reduced levels of adenosine triphosphate and mitochondrial membrane potential, and increased reactive oxygen species production were observed in mutant peripheral blood mononuclear cells (all P < 0.05). Linear regression analysis indicated that higher heteroplasmy levels in peripheral blood leukocytes were associated with increased levels of glycated albumin and HbA_1c , and decreased total hip bone mineral density T-score after adjustment for age and sex (all P < 0.05). Furthermore, mitochondrial membrane potential was independently associated with bone mineral density T-score at the femoral neck (P < 0.05).

CONCLUSIONS

Heteroplasmy levels in peripheral blood leukocytes and mitochondrial membrane potential in peripheral blood mononuclear cells were closely associated with clinical manifestations and were valuable for evaluation of the clinical severity of the m.3243A>G mutation.

The UNICEF/Washington Group Child Functioning Module-Accuracy, Inter-Rater Reliability and Cut-Off Level for Disability Disaggregation of Fiji's Education Management Information System

This paper explores the validity (sensitivity and specificity) of different cut-off levels of the UNICEF/Washington Group Child Functioning Module (CFM) and the inter-rater reliability between teachers and parents as proxy respondents, for disaggregating Fiji's education management information system (EMIS) by disability. The method used was a cross-sectional diagnostic accuracy study comparing CFM items to standard clinical assessments for 472 primary school aged students in Fiji. Whilst previous domain-specific results showed "good" to "excellent" accuracy of the CFM domains seeing, hearing, walking and speaking, newer analysis shows only "fair" to "poor" accuracy of the cognitive domains (learning, remembering and focusing attention) and "fair" of the overall CFM (area under the Receiver Operating Characteristic curve: 0.763 parent responses, 0.786 teacher responses). Severe impairments are reported relatively evenly across CFM response categories "some difficulty", "a lot of difficulty" and "cannot do at all". Most moderate impairments are reported as "some difficulty". The CFM provides a core component of data required for disaggregating Fiji's EMIS by disability. However, choice of cut-off level and mixture of impairment severity reported across response categories are challenges. The CFM alone is not accurate enough to determine funding eligibility. For identifying children with disabilities, the CFM should be part of a broader data collection including learning and support needs data and undertaking eligibility verification visits.

Contributing factors to high prevalence of hearing impairment in the Elias Motsoaledi Local Municipal area, South Africa: A rural perspective

Background

There is evidence that the factors contributing to the prevalence and aetiology of hearing impairment vary widely from one country to another. In South Africa, as in other low-income and middle-income countries, more context-specific information on the estimated prevalence of hearing impairment and the factors that contribute to its onset is required.

Aim

The aim of this study was to provide decision-makers and hearing health professionals with local and accurate information on the prevalence of ear and hearing disorders in the Elias Motsoaledi Local Municipal (EMLM) area of the Limpopo province, South Africa.

Methods

The World Health Organization (WHO) protocol for population-based surveys of prevalence and causes of deafness, hearing impairment and other ear diseases was utilised. A random multi-stage cluster sampling strategy, two-stage sampling, was utilised to select the seven municipal wards and 357 households through the probability proportional to size method. A total of 850 participants were included in the study.

Results

The overall prevalence of hearing impairment was 19.88% (95% confidence interval [CI]: 0.15–0.2) and 8.94 (95% CI: 0.08–0.12) for disabling hearing impairment. The prevalence of ear disease was 13.19% (95% CI: 0.10–0.15), with impacted cerumen and otitis media reported most often. Associations with hearing impairment were established for age, gender and hypertension.

Conclusion

The study has shown a higher prevalence of disabling hearing impairment in the rural EMLM area of the Limpopo province compared to global prevalence rates. In addition, known factors associated with hearing impairment were confirmed.

ENT in the context of global health

Global health is a fashionable term frequently used in the twenty-first century's news that is rarely understood by ear, nose and throat (ENT) professionals. Communicable diseases such as HIV, tuberculosis and malaria have been in the headlines of global health for decades. Despite the recent public health concerns about noncommunicable diseases, including ENT disorders, these disorders still receive little attention on the global health stage. Despite the 'benign' nature and a large number of patients affected at a given time, noncommunicable diseases were found to account for 60% of international mortality in 2008. More specifically to ENT, disabling hearing impairment has been found to be the most common disability globally. Therefore, it is now critical for otolaryngologists worldwide to get involved in the overlooked ENT global issues. This article discusses the main challenges faced by the ENT community in the developing world and proposes what can be done to help.

De Novo Mutation of m.3243A>G together with m.16093T>C Associated with Atypical Clinical Features in a Pedigree with MIDD Syndrome

BACKGROUND

The syndrome of maternally inherited diabetes and deafness (MIDD) is typically caused by the m.3243A>G mutation and widely considered maternally inherited. In our study, we aimed to investigate the heredity way of the m.3243A>G among pedigrees with MIDD and discover novel mitochondrial DNA mutations related to atypical clinical phenotypes.

METHODS

Heteroplasmy levels of the m.3243A>G mutation in peripheral blood, saliva, and urine sediment of 31 individuals from 10 unrelated pedigrees were measured by pyrosequencing. Clinical evaluations including endocrinological, audiological, and magnetic resonance imaging (MRI) examinations, mitochondrial function evaluation in peripheral blood mononuclear cells (PBMCs), and whole mitochondrial DNA (mtDNA) sequencing were performed among the spontaneous mutant pedigrees.

RESULTS

Among the 10 unrelated MIDD pedigrees, we found that the de novo m.3243A>G mutation occurred in the family 1957 (F1957). The proband (F1957-II-1) and her son (F1957-III-1) both manifested diabetes with mild bilateral sensorineural hearing loss (SNHL) and abnormal brain MRI, and F1957-III-1 also complained of severe nausea and vomiting. Mitochondrial function evaluation in PBMCs revealed an increased level of ROS generation and decreased levels of ATP and mitochondrial membrane potential (ΔΨm) in the two m.3243A>G carriers. Whole mtDNA sequencing also revealed a de novo heteroplasmic substitution at m.16093T>C in both the proband and her son.

CONCLUSIONS

Our study showed that de novo m.3243A>G mutation accompanied by other point mutations may occur in the very early embryonic or germ cell stage without maternal inheritance, bringing about both typical and atypical clinical features.

Validating the UNICEF/Washington Group Child Functioning Module for Fijian schools to identify seeing, hearing and walking difficulties

PURPOSE

This study investigated the seeing, hearing and walking questions of the UNICEF/Washington Group Child Functioning Module and the inter-rater reliability between teachers and parents as proxy respondents.

METHODS

Cross-sectional diagnostic accuracy study, two-gate design with representative sampling, comparing Module responses to reference standard assessments for 472 primary aged students in Fiji. Receiver operating characteristic curves were constructed to determine the area under the curve and optimal cut-off points.

RESULTS

Areas under the curves ranged from 0.823 to 0.889 indicating "good" diagnostic accuracy. Inter-rater reliability between parent and teacher responses was "good" to "excellent". The optimal cut-off determined by the Youden Index was "some difficulty" however a wide spread of impairment levels were found in this category with most children either having none or substantial impairments.

CONCLUSIONS

The diagnostic accuracy of the Module seeing, hearing and walking questions appears acceptable with either parents or teachers as proxy respondents. For education systems, use of the cut-off "some difficulty" with accompanying clinical assessment may be important to capture children who require services and learning supports and avoid potentially misleading categorization. Given the high proportion of the sample from special schools research is required to further test the Module in mainstream schools. Implications for rehabilitation Identification of children who are at risk of disability in Fiji is important to enable planning, monitoring and evaluating access to quality inclusive education. The UNICEF/Washington Group Child Functioning Module appears to be a practical and effective tool that can be used by teachers to identify children at risk of disability. Children identified on the UNICEF/Washington Group Child Functioning Module as having "some difficulty" or higher levels of difficulty in relation to vision, hearing or walking should be referred for further assessment and services. Rehabilitation services in Fiji need to prepare for greater numbers of referrals as the Ministry of Education increasingly rolls out the inclusive education policy, which includes identification by schools of children at risk of disability.

Cardiovascular risk factors and hearing loss among adults in a tertiary center of Northwestern Nigeria

Objective

To assess the effect of cardiovascular risk factors on hearing impairment.

Methods

This was a cross sectional study conducted in Usmanu Danfodiyo University Teaching Hospital, Sokoto. A pretested questionnaire was used to obtain information about the biodata and medical history of participants after which, they were examined and had their hearing thresholds measured.

Results

In this study, total of 220 participants were recruited. Within these participants, 112 (55.5%) were females, while 98 (44.5%) were males. The average age of the participants was (45.24 ± 12.21) years. The mean of pure tone average among the participants was (19.15 ± 9.28) dB HL. Thirty-six (16.4%) of the participants had some degree of hearing loss. Besides, 30 of them (13.6%) had hypertension, while 23 (10.5%) presented with diabetes mellitus. In addition, 43 participants (19.5%) had BMI (body mass index) that was ≥25 kg/m². Also, 9 out of the 220 participants (4.1%) had a history of cigarette smoking. Our studies indicated that hypertension, diabetes mellitus, BMI of ≥25 kg/m², and aging were significantly associated with the risk of hearing loss. In contrast, cigarette smoking and sex were not associated with the hearing loss.

Conclusion

This study showed that hypertension, diabetes mellitus, aging, and higher BMI were associated with increase risk of hearing loss.

Prevalence and causes of hearing impairment in Fundong Health District, North-West Cameroon

OBJECTIVE

To estimate the prevalence and causes of hearing impairment in Fundong Health District, North-West Cameroon.

METHODS

We selected 51 clusters of 80 people (all ages) through probability proportionate to size sampling. Initial hearing screening was undertaken through an otoacoustic emission (OAE) test. Participants aged 4+ years who failed this test in both ears or for whom an OAE reading could not be taken underwent a manual pure-tone audiometry (PTA) screening. Cases of hearing impairment were defined as those with pure-tone average ≥41 dBHL in adults and ≥35 dBHL in children in the better ear, or children under age 4 who failed the OAE test in both ears. Each case with hearing loss was examined by an ear, nose and throat nurse who indicated the main likely cause.

RESULTS

We examined 3567 (86.9%) of 4104 eligible people. The overall prevalence of hearing impairment was 3.6% (95% confidence interval [CI]: 2.8-4.6). The prevalence was low in people aged 0-17 (1.1%, 0.7-1.8%) and 18-49 (1.1%, 0.5-2.6%) and then rose sharply in people aged 50+ (14.8%, 11.7-19.1%). Among cases, the majority were classified as moderate (76%), followed by severe (15%) and profound (9%). More than one-third of cases of hearing impairment were classified as unknown (37%) or conductive (37%) causes, while sensorineural causes were less common (26%).

CONCLUSIONS

Prevalence of hearing impairment in North-West Cameroon is in line with the WHO estimate for sub-Saharan Africa. The majority of cases with known causes are treatable, with impacted wax playing a major role.

Otoacoustic Emissions in Rural Nicaragua: Cost Analysis and Implications for Newborn Hearing Screening

Objective (1) Determine the incidence and risk factors for congenital hearing loss. (2) Perform cost analysis of screening programs. Study Design Proportionally distributed cross-sectional survey. Setting Jinotega, Nicaragua. Subjects and Methods Otoacoustic emissions (OAEs) were used to screen 640 infants <6 months of age from neonatal intensive care unit, institutional, and home birth settings. Data on 15 risk factors were analyzed. Cost of 4 implementation strategies was studied: universal screening, screening at the regional health center (RHC), targeted screening, and screening at the RHC plus targeted screening. Cost-effectiveness analysis over 10 years was based on disability-adjusted life year estimates, with the World Health Organization standard of cost-effectiveness ratio (CER) / gross domestic product (GDP) <3, with GDP set at $4884.15. Results Thirty-eight infants failed the initial OAE (5.94%). In terms of births, 325 (50.8%) were in the RHC, 69 (10.8%) in the neonatal intensive care unit, and 29 (4.5%) at home. Family history and birth defect were significant in univariate analysis; birth defect was significant in multivariate analysis. Cost-effectiveness analysis demonstrated that OAE screening is cost-effective without treatment (CER/GDP = 0.06-2.00) and with treatment (CER/GDP = 0.58-2.52). Conclusions Our rate of OAE failures was comparable to those of developed countries and lower than hearing loss rates noted among Nicaraguan schoolchildren, suggesting acquired or progressive etiology in the latter. Birth defects and familial hearing loss correlated with OAE failure. OAE screening of infants is feasible and cost-effective in rural Nicaragua, although highly influenced by estimated hearing loss severity in identified infants and the high travel costs incurred in a targeted screening strategy.

Overview of a public health approach to pediatric hearing impairment in the Pacific Islands

BACKGROUND

Childhood hearing impairment is a significant cause of disability in developing countries. Otitis media and meningitis are leading infectious causes of preventable hearing loss in children. It is estimated that the Pacific Islands have among the greatest global burden of childhood hearing impairment due to infectious causes, and yet there is currently very little in the research literature on pediatric hearing disorders in this region.

OBJECTIVES

(1) To review existing research literature on pediatric hearing impairment in the Pacific Islands, and (2) to present a public health approach to the development and improvement of childhood hearing services in the Pacific Islands.

DATA

The primary tool was a comprehensive literature review. MEDLINE and ScienceDirect databases were searched for relevant journal articles. There was no limit on the date of publication. Any article reporting on hearing impairment in the Pacific Region was included.

RESULTS

A total of 23 journal articles were found that satisfied the above inclusion criteria. The limited information available in the literature suggests that otitis media and vaccine-preventable infections are a significant cause of avoidable childhood hearing impairment in the Pacific Islands. Pediatric audiology services are limited in this region. Further research is required to develop effective public health programs that should reduce the burden of preventable childhood hearing loss in the Pacific Islands.

CONCLUSIONS

There is limited information in the research literature on pediatric hearing impairment and audiology services in the Pacific Islands. Epidemiological data based on the WHO Ear and Hearing Disorders Survey Protocol are urgently needed, and the development of audiology services within the existing public and primary health care framework should reduce the burden of preventable hearing loss in the Pacific Islands.

Cost Effectiveness of Childhood Cochlear Implantation and Deaf Education in Nicaragua: A Disability Adjusted Life Year Model

INTRODUCTION

Cochlear implantation (CI) is a common intervention for severe-to-profound hearing loss in high-income countries, but is not commonly available to children in low resource environments. Owing in part to the device costs, CI has been assumed to be less economical than deaf education for low resource countries. The purpose of this study is to compare the cost effectiveness of the two interventions for children with severe-to-profound sensorineural hearing loss (SNHL) in a model using disability adjusted life years (DALYs).

METHODS

Cost estimates were derived from published data, expert opinion, and known costs of services in Nicaragua. Individual costs and lifetime DALY estimates with a 3% discounting rate were applied to both two interventions. Sensitivity analysis was implemented to evaluate the effect on the discounted cost of five key components: implant cost, audiology salary, speech therapy salary, number of children implanted per year, and device failure probability.

RESULTS

The costs per DALY averted are $5,898 and $5,529 for CI and deaf education, respectively. Using standards set by the WHO, both interventions are cost effective. Sensitivity analysis shows that when all costs set to maximum estimates, CI is still cost effective.

CONCLUSION

Using a conservative DALY analysis, both CI and deaf education are cost-effective treatment alternatives for severe-to-profound SNHL. CI intervention costs are not only influenced by the initial surgery and device costs but also by rehabilitation costs and the lifetime maintenance, device replacement, and battery costs. The major CI cost differences in this low resource setting were increased initial training and infrastructure costs, but lower medical personnel and surgery costs.

MMP-9 gene ablation mitigates hyperhomocystenemia-induced cognition and hearing dysfunction

Hyperhomocysteinemia (HHcy) is associated with cognitive decline and hearing loss due to vascular dysfunction. Although we have shown that HHcy-induced increased expression of matrix metalloproteinase-9 (MMP-9) is associated with cochlear pathology in cystathionine-β-synthase heterozygous (CBS(+/-)) mice, it is still unclear whether MMP-9 contributes to functional deficit in cognition and hearing. Therefore, we hypothesize that HHcy-induced MMP-9 activation causes vascular, cerebral and cochlear remodeling resulting in diminished cognition and hearing. Wildtype (WT), CBS(+/-), MMP-9(-/-) and CBS(+/-)/MMP-9(-/-) double knock-out (DKO) mice were genotyped and used. Doppler flowmetry of internal carotid artery (ICA) was performed for peak systolic velocity [PSV], pulsatility index [PI] and resistive index [RI]. Cognitive functions were assessed by Novel Object Recognition Test (NORT) and for cochlear function Auditory brainstem response (ABR) was elicited. Peak systolic velocity, pulsatility and resistive indices of ICA were decreased in CBS(+/-) mice, indicating reduced perfusion. ABR threshold was increased and maximum ABR amplitude and NORT indices (recognition, discrimination) were decreased in CBS(+/-) mice compared to WT and MMP-9(-/-). All these parameters were attenuated in DKO mice suggesting a significant role of MMP-9 in HHcy-induced vascular, neural and cochlear pathophysiology. Regression analysis of PSV with ABR and cognitive parameters revealed significant correlation (0.44-0.58). For the first time, MMP-9 has been correlated directly to functional deficits of brain and cochlea, and found to have a significant role. Our data suggests a dual pathology of HHcy occurring due to a decrease in blood supply (vasculo-neural and vasculo-cochlear) and direct tissue remodeling.

Genetics of hearing loss in Africans: use of next generation sequencing is the best way forward

Hearing loss is the most common communication disorder affecting about 1-7/1000 births worldwide. The most affected areas are developing countries due toextensively poor health care systems. Environmental causes contribute to 50-70% of cases, specifically meningitis in sub-Saharan Africa. The other 30-50% is attributed to genetic factors. Nonsyndromic hearing loss is the most common form of hearing loss accounting for up to 70% of cases. The most common mode of inheritance is autosomal recessive. The most prevalent mutations associated with autosomal recessive nonsyndromic hearing loss (ARNSHL) are found within connexin genes such as GJB2, mostly in people of European and Asian origin. For example, the c.35delG mutation ofGJB2 is found in 70% of ARNSHL patients of European descentand is rare in populations of otherethnicities. Other GJB2 mutations have been reported in various populations. The second most common mutations are found in theconnexin gene, GJB6, also with a high prevalencein patients of European descent. To date more than 60 genes have been associated with ARNSHL. We previously showed that mutations in GJB2, GJB6 and GJA1 are not significant causes of ARNSHL inpatients from African descents, i.e. Cameroonians and South AfricansIn order to resolve ARNSHL amongst sub-Saharan African patients, additional genes would need to be explored. Currently at least 60 genes are thought to play a role in ARNSHL thus the current approach using Sanger sequencing would not be appropriate as it would be expensive and time consuming. Next Generation sequencing (NGS) provides the best alternative approach. In this review, we reported on the success of using NGSas observed in various populations and advocate for the use of NGS to resolve cases of ARNSHL in sub-Saharan African populations.

A possible molecular mechanism of hearing loss during cerebral ischemia in mice

Ischemic brain stroke is a leading cause of disability and includes hearing loss. Clinical reports have also suggested that there is hearing loss in stroke patients but the mechanism was not determined. Therefore, we hypothesized that hearing loss after cerebral ischemia may be associated with changes to the synapse, gap junction, and sodium channel (NaC) proteins. Ischemia-reperfusion injury was induced in wild-type mice (I/R group). The lesion volume was determined by 2,3,5-triphenyltetrazolium chloride (TTC) staining of the brain sections. BBB disruption was confirmed by Evans blue staining and leakage of bovine serum albumin labeled with fluorescein isothiocyanate (BSA-FITC). We found that brain edema, infarct size, and permeability were increased in ischemic mice as compared with the sham-operated group. Caspase-3, caspase-9, and TUNEL-positive cells were increased in I/R mice, indicating neuronal apoptosis. Moreover, there were increased expressions of matrix metalloprotease's (MMP-2, -3, -9, and -13), interleukin (IL)-6, and decreased expressions of tight junction proteins (TJP) in the I/R group, as compared with the sham group, which signifies inflammation and BBB disruption. We also observed decreased levels of post-synaptic density protein-95 (PSD-95), synapse-associated protein 97 (SAP-97), connexin-43, NaC-α, and NaC-β, and increased expression of connexin-45, whereas no substantial change was observed in connexin-26 expression in the I/R group. Interestingly, auditory response was reduced in the I/R mice, indicating hearing loss. These data suggest that hearing loss in ischemic mice was primarily due to alterations in connexin, synapses, and NaC channels.

Assessment of hearing loss by pure-tone audiometry in patients with mucopolysaccharidoses

BACKGROUND

Patients with mucopolysaccharidoses (MPS) often have hearing loss. However, the characterization of hearing loss by pure-tone audiometry (PTA) in this rare disease population and its relationship to age and treatment is limited.

METHODS

PTA was performed in 39 patients with MPS (29 males and 10 females; 3 with MPS I, 21 with MPS II, 9 with MPS IVA, and 6 with MPS VI; median age, 11.9 years; age range, 4.4-34.2 years). The degree of hearing loss was classified by the age-independent World Health Organization (WHO) clinical guidelines.

RESULTS

Hearing loss by PTA was present in 85% (33/39) of patients and was categorized as mild (26-40 dB) in 18%, moderate (41-60 dB) in 36%, severe (61-80 dB) in 23%, and profound (≥81dB) in 5%. Among the patients with hearing loss, 33% were classified as mixed type (conductive and sensorineural), 30% as pure conductive type, 27% as pure sensorineural type, and 9% were undefined. The means of the right and left ear hearing thresholds at 2000 and 4000 Hz by air conduction (AC) and at 500, 1000, 2000, and 4000 Hz by bone conduction (BC) were all positively correlated with age (p<0.05). In the 6 patients with MPS II or VI who underwent follow-up PTA after ventilation tube insertion and enzyme replacement therapy for 1.9 to 8.5 years, all showed improvements in AC and BC of the better ear, as well as in the air-bone gap.

CONCLUSIONS

Hearing impairment is common in MPS. Early otolaryngological evaluation and intervention are recommended. These findings and the follow-up data can be used to develop quality of care strategies for patients with MPS.

Survey of Otolaryngology Services in Central America

In the developing world, there exists a scarcity of services and training in otolaryngology, audiology, and speech therapy, which is reflected by the gap between health care delivery in high-income countries and low-income countries. We surveyed, by questionnaire, the countries of Central America, except for Belize, because of the lack of otolaryngology services, on the following issues: availability of otolaryngology, audiology, and speech therapy services and equipment; otolaryngologist, audiologist, and speech therapist training; and availability of services in rural areas. Surveys were distributed via email and by hand at the 2011 Central American Congress of Otolaryngology, in San Salvador, El Salvador, to otolaryngologists, audiologists, and speech therapists. Not to our surprise, there is a shortfall in services and training in all three professions. The data collected and presented in this commentary will provide a basis by which change might take place.

The impact of Hunter syndrome (mucopolysaccharidosis type II) on health-related quality of life

Background

Hunter syndrome (mucopolysaccharidosis type II (MPS II)) is a rare metabolic disease that can severely compromise health, well-being and life expectancy. Little evidence has been published on the impact of MPS II on health-related quality of life (HRQL). The objective of this study was to describe this impact using the Hunter Syndrome-Functional Outcomes for Clinical Understanding Scale (HS-FOCUS) questionnaire and a range of standard validated questionnaires previously used in paediatric populations.

Methods

Clinical and demographic characteristics collected in a clinical trial and responses to four HRQL questionnaires completed both by patients and parents prior to enzyme replacement treatment were used. The association between questionnaire scores and clinical function parameters were tested using Spearman rank-order correlations. Results were compared to scores in other paediatric populations with chronic conditions obtained through a targeted literature search of published studies.

Results

Overall, 96 male patients with MPS II and their parents were enrolled in the trial. All parents completed the questionnaires and 53 patients above 12 years old also completed the self-reported versions. Parents’ and patients’ responses were analysed separately and results were very similar. Dysfunction according to the HS-FOCUS and the CHAQ was most pronounced in the physical function domains. Very low scores were reported in the Self Esteem and Family Cohesion domains in the CHQ and HUI3 disutility values indicated a moderate impact. Scores reported by patients and their parents were consistently lower than scores in the other paediatric populations identified (except the parent-reported Behaviour score); and considerably lower than normative values.

Conclusions

This study describes the impact on HRQL in patients with MPS II and provides a broader context by comparing it with that of other chronic paediatric diseases. Physical function and the ability to perform day-to-day activities were the most affected areas and a considerable impact on the psychological aspects of patients’ HRQL was also found, with a higher level of impairment across most dimensions (particularly Pain and Self Esteem) than that of other paediatric populations. Such humanistic data provide increasingly important support for establishing priorities for health care spending, and as a component of health economic analysis.

Quality of life measures in otitis media

Disabling hearing impairment is the world's most common disability. Traditionally, hearing levels measured by pure tone audiometry have been used to define and quantify hearing loss. The effects of disabling hearing loss on patients' quality of life can be profound, and audiometric data alone may not correlate with quality of life measures. Generic measures of quality of life can be used to compare different diseases, and as such are useful in resource allocation and burden of disease studies. Their disadvantage is that they are not disease-specific and can therefore under-estimate the effects of a disease on patients' quality of life. Disease-specific measures are more sensitive. In chronic otitis media, additional factors such as discharge augment the effect of hearing loss alone on quality of life. Many of the quality of life measures developed for chronic otitis media have been used to assess improvement following reconstructive surgery. Quality of life measures have also been used to assess the effect of paediatric otitis media. Quality of life measures also have utility in the developing world, where hearing impairment is a huge burden.

The Hunter syndrome-functional outcomes for clinical understanding scale (HS-FOCUS) questionnaire: evaluation of measurement properties

PURPOSE

This study was to conduct the psychometric validation of the patient and parent versions of the Hunter syndrome-functional outcomes for clinical understanding scale (HS-FOCUS).

METHODS

Data collected in a 53-week placebo-controlled multinational trial were used to evaluate item performance and reliability, validity, and ability to detect change of the six HS-FOCUS function domains.

RESULTS

HS-FOCUS was completed by 49 patients above 12 years old and 84 parents. Floor effects and high average inter-item correlations suggested that some items were less informative or redundant. For both patients and parents, the internal consistency and test-retest reliability met the >0.70 criteria for all domains except for the breathing, sleeping, and schooling/work in patients. Construct validity showed moderate to high correlations with CHAQ, CHQ, and HUI3 in activity-related concepts. Significant differences in domain scores were found in most domains among severity in disability measured by CHAQ DIS. Significant differences in HS-FOCUS change scores were found in patients whose CHAQ DIS score also changed.

CONCLUSIONS

Psychometric validation of the HS-FOCUS demonstrates it is a reliable, valid, and responsive instrument that can be applied in clinical trials or disease registries. Findings on the individual item performance suggest some items could be removed without compromising its validity.

Hearing loss in patients with mucopolysaccharidosis II: data from HOS - the Hunter Outcome Survey

BACKGROUND

Subjectively reported hearing loss is a common feature of mucopolysaccharidosis II (MPS II, Hunter syndrome). This study provides an epidemiological description of hearing loss and other otolaryngological manifestations reported by patients registered in the Hunter Outcome Survey (HOS), an international registry of patients with MPS II.

METHODS

Data about ear signs and symptoms were available for 554 of the 605 patients alive at HOS entry. The degree of hearing loss for 162 pure-tone audiograms (PTAs) from 83 patients was classified by independent interpreters using both the age-specific International Institute of Standardization (ISO) 7029 standard and the age-independent World Health Organization (WHO) clinical guidelines. A linear regression analysis using cross-sectional data was conducted to investigate the relationship between hearing loss and age.

RESULTS

The most prevalent otolaryngological manifestations and interventions reported were otitis (either acute otitis media or chronic otitis media [72%]), hearing loss (67%), insertion of ventilation tubes (50%), adenoidectomy (47%), and hearing aids (41%). According to the ISO standard, only one patient out of the 83 with audiogram data in HOS had normal hearing in both ears at all time points. According to the WHO classification, 16% had normal hearing; hearing loss was mild in 24%, moderate in 31%, severe in 22%, and profound in 7%. In the linear regression analysis, the hearing threshold in the cohort increased with age at an estimated rate of approximately 1 dB per year.

CONCLUSIONS

Hearing impairment is common in MPS II. Early otolaryngological evaluation and intervention is recommended.

Evaluating a Dichotomized Measure of Self-Reported Hearing Loss Against Gold Standard Audiometry

Objectives: To evaluate a harmonized binary measure of self-reported hearing loss against gold standard audiometry in an older adult population. Method: Seven nationally representative population-based studies were harmonized and pooled ( n = 23,001). Self-report items were recoded into a dichotomous format. Audiometric hearing loss was defined by averaged pure-tone thresholds greater than 25-decibel hearing level in the better ear. We compared age and sex stratified prevalence rates of hearing loss estimated by self-report and audiometric measures. Results: Overall, 56% of men and 43% of women had audiometric hearing loss. There were moderate associations between self-reported and audiometric hearing loss. However, prevalence based on self-report was overestimated for adults aged below 70 years and underestimated for adults aged above 75. Discussion: Self-report of hearing loss is insensitive to age effects and does not provide a reliable basis for estimating prevalence of age-related hearing loss, although may indicate perceived hearing disability.

Global and regional hearing impairment prevalence: an analysis of 42 studies in 29 countries

BACKGROUND

Hearing impairment is a leading cause of disease burden, yet population-based studies that measure hearing impairment are rare. We estimate regional and global hearing impairment prevalence from sparse data and calculate corresponding uncertainty intervals.

METHODS

We accessed papers from a published literature review and obtained additional detailed data tabulations from investigators. We estimated the prevalence of hearing impairment by region, sex, age and hearing level using a Bayesian hierarchical model, a method that is effective for sparse data. As the primary objective of modelling was to produce regional and global prevalence estimates, including for those regions with scarce to no data, models were evaluated using cross-validation.

RESULTS

We used data from 42 studies, carried out between 1973 and 2010 in 29 countries. Hearing impairment was positively related to age, male sex and middle- and low-income regions. We estimated that the global prevalence of hearing impairment (defined as an average hearing level of 35 decibels or more in the better ear) in 2008 was 1.4% (95% uncertainty interval 1.0-2.2%) for children aged 5-14 years, 9.8% (7.7-13.2%) for females >15 years of age and 12.2% (9.7-16.2%) for males >15 years of age. The model exhibited good external validity in the cross-validation analysis, with 87% of survey estimates falling within our final model's 95% uncertainty intervals.

CONCLUSION

Our results suggest that the prevalence of child and adult hearing impairment is substantially higher in middle- and low-income countries than in high-income countries, demonstrating the global need for attention to hearing impairment.

Envelhecimento e deficiência auditiva referida: um estudo de base populacional

O objetivo do estudo foi estimar a prevalência da deficiência auditiva referida por idosos do Município de São Paulo, Brasil, segundo características sociodemográficas e descrever características atribuídas a esta deficiência. Os dados são provenientes do Inquérito de Saúde do Município de São Paulo (ISA-Capital/2003), com análise do subgrupo dos idosos (n = 872). Realizaram-se o teste do χ2 e a análise de regressão de Poisson. A prevalência da deficiência auditiva referida pelos idosos foi 11,2% e foi maior entre os homens (RP = 1,86; IC95%: 1,19-2,92). Observou-se grande desconhecimento dos idosos quanto às causas da deficiência auditiva referida (42,5%), 25,5% relataram ter dificuldades em atividades de lazer, 11,4% necessitavam de ajuda para atividades cotidianas e 63,3% relataram não necessitar de assistência em decorrência deste déficit. A alta prevalência de deficiência auditiva referida pelos idosos, principalmente do sexo masculino, remete à relevância deste problema para a saúde pública, já que o envelhecimento populacional é uma realidade nova e vem acompanhada de exigências ainda desconhecidas por profissionais e pelo poder público.

Evidence of hearing loss in a 'normally-hearing' college-student population

We report pure-tone hearing threshold findings in 56 college students. All subjects reported normal hearing during telephone interviews, yet not all subjects had normal sensitivity as defined by well-accepted criteria. At one or more test frequencies (0.25-8 kHz), 7% of ears had thresholds ≥25 dB HL and 12% had thresholds ≥20 dB HL. The proportion of ears with abnormal findings decreased when three-frequency pure-tone-averages were used. Low-frequency PTA hearing loss was detected in 2.7% of ears and high-frequency PTA hearing loss was detected in 7.1% of ears; however, there was little evidence for 'notched' audiograms. There was a statistically reliable relationship in which personal music player use was correlated with decreased hearing status in male subjects. Routine screening and education regarding hearing loss risk factors are critical as college students do not always self-identify early changes in hearing. Large-scale systematic investigations of college students' hearing status appear to be warranted; the current sample size was not adequate to precisely measure potential contributions of different sound sources to the elevated thresholds measured in some subjects.

Cochlear Implantation in Developing Countries as Humanitarian Service

Objective. To make recommendations concerning cochlear implantation during humanitarian medical trips by exploring the attitudes of US cochlear implant surgeons.

Study Design. Cross-sectional survey.

Setting. Academic.

Subjects and Methods. Questionnaires were sent to 405 members of the William House Cochlear Implant Study Group. The 198 respondents (49%), all active cochlear implant surgeons, were divided into 3 groups depending on their level of experience working in a developing country.

Results. Eighty-nine percent of respondents supported cochlear implants in these environments, although 42% of these cochlear implant surgeons stated that they would modify their criteria for implantation considering the challenges in developing countries. There was strong support for cochlear implants in postlingual deafened patients and prelingual deafened patients under the age of 3 years, although nearly half of respondents (48%) would not implant prelingual deafened patients after they reached the age of 3 years. Three-quarters of respondents (74%) believed that developing countries should have the same access to current multichannel devices used in developed countries, as opposed to simpler, possibly lower cost devices. A local audiologist was deemed the most important personnel requirement (83%), and limited audiology and rehabilitative resources were the greatest postoperative concern rather than lack of postoperative care or infection.

Conclusion. This survey strongly supports the practice of performing cochlear implants during humanitarian trips to developing countries and makes best-practice recommendations to make outcomes successful.