Prevalence of hearing loss and ear morbidity among adolescents and young adults in rural southern Nepal

Early childhood height is a determinant of young adult stature in rural Nepal

BACKGROUND

Does preschool height predict adult stature in undernourished settings? The extent to which preschool length or height forecasts young adult stature is unclear in chronically undernourished populations.

METHODS

In 2006-8, we assessed height in a cohort of 2074 young adults, aged 16-23 years, in rural Nepal who, as preschoolers (≤ 4 year), were measured at baseline and again 16 months later during a vitamin A supplementation trial in 1989-91. We assessed by linear regression the ability of preschool length (L, measured < 24 mo) or height (Ht, 24-59 mo), at each year of age to predict 16-23 year old height, adjusted for month of young adult age, interval duration (in months), caste, preschool weight-for-height z-score and, in young women, time since menarche, marriage status and pregnancy history.

RESULTS

Young women were a mean of 0.81, 1.11, 0.82, 0.24, 0.44 cm taller (all p < 0.01) and young men, 0.84, 1.18, 0.74, 0.64 and 0.48 cm taller (all p < 0.001) per cm of attained L/Ht at each successive preschool year of age and, overall, were 2.04 and 2.40 cm taller for each unit increase in preschool L/Ht z-score (L/HAZ) (both p < 0.001). Coefficients were generally larger for 16-month follow-up measurements. The percent of young adult height attained by children with normal L/HAZ (>-1) increased from 38-40% mid-infancy to ∼ 69-74% by 6 years of age. By 3-6 years of age heights of stunted children (L/HAZ<-2) were consistently ∼ 4-7% lower in their young adult height versus normal statured children. There was no effect of preschool vitamin A receipt.

CONCLUSIONS

Shorter young children become shorter adults but predictive effects can vary by sex, age assessed, and may be influenced by year or season of measurement.

Assessment of the Hearing Status of School-Age Children from Rural and Urban Areas of Mid-Eastern Poland

(1) Background: The purpose of this study was to assess the prevalence of hearing loss in school-age children from rural and urban areas of mid-eastern Poland using standard audiological tests-pure tone audiometry (PTA), impedance audiometry (IA), and otoacoustic emissions (OAEs). (2) Methods: Data were collected from a group of 250 children aged 8 to 13, made up of 122 children from urban areas and 128 children from rural areas of mid-eastern Poland. Hearing was assessed in each of the subjects by means of PTA, IA (tympanometry), and transient-evoked OAEs (TEOAEs). Otoscopy was also performed. (3) Results: There were significantly fewer abnormal results in children from urban than rural areas: they were, respectively, 10.1% and 23.1% for IA, 3% and 9.7% for PTA, and 17.3% and 31.8% for TEOAEs. For hearing-impaired ears in rural areas (failed TEOAE), hearing thresholds were, on average, 11.5 dB higher at 0.5 kHz than for children in urban areas. Comparison of each PTA result with the corresponding IA showed that all cases of hearing loss were related to malfunction of the middle ear. (4) Conclusions: The results of all three hearing tests were significantly worse in children from rural areas compared to those from urban areas. This indicates that audiological healthcare in rural areas needs improvement and that universal hearing screening programs for school-age children would be helpful.

Prevalence of hearing loss in school aged Nepalese children

OBJECTIVES

The main objective of this study is to identify the prevalence of hearing loss in school aged children of Nepal.

METHODS

This cross-sectional study was carried out on school aged children attending the government run schools of Nepal. A total of 79,340 children from grades 1 through 10 were included in the study. After taking brief history about ear diseases and hearing loss, children were screened for ear diseases in their respective classroom by otoscope. Hearing evaluation was carried out by pure tone audiometer and hearing threshold was obtained at 0.5-4 kHz. The results were then documented and analyzed.

RESULTS

The prevalence of hearing impairment in school aged children in Nepal is found to be 5.73% (4551 of 79,340). Conductive hearing loss was the most common type of hearing loss and was observed in 70.47% (n = 3207) of the children.

CONCLUSIONS

This study shows that hearing loss is a common problem in children of Nepal. With the main cause of hearing loss due to preventable conditions such as chronic otitis media, it is believed that early standardized screening, detection and timely management of chronic otitis media in these children can prevent hearing loss and its impact on their educational, social and language development. School based ear health programs are a useful community-oriented solution for prevention of deafness. It shows how important it is to introduce hearing screening for primary school aged children to prevent hearing loss.

Association of anemia with sensorineural hearing loss: a systematic review and meta-analysis

OBJECTIVE

Evidence shows that anemic individuals are at a higher risk of hearing loss. However, there is no systematic review and meta-analysis study. Thus, we aimed to meta-analyze the existing evidence on the association of iron deficiency anemia (IDA) with sensorineural hearing loss (SNHL). We searched PubMed, MEDLINE, Embase, Scopus, and Google Scholar from inception through October 30, 2017, for studies done on the association of the IDA with SNHL. Pooled odds ratio (OR) was calculated by random effect meta-analysis method. Heterogeneity was assessed by I² metrics.

RESULT

Four studies, covering a total of 344,080 adults and children, were included. The odds of SNHL was higher by 55% in individuals with IDA, compared with individuals without IDA (OR = 1.55, 95% CI 1.17-2.06; P = 0.03). The age-specific ORs were 1.36 (95% CI 1.15-1.61; P = 0.27) and 3.67 (95% CI 1.72-7.84) for adults and children, respectively. IDA may be a contributing factor to hearing loss. Further studies are warranted, including whether IDA treatment reduces the risk of hearing loss. Meanwhile, hearing loss screening in anemic individuals, or vice versa, may represent an important consideration. PROSPERO registration CRD42017082108.

Association of Nutritional Factors with Hearing Loss

Hearing loss (HL) is a major public health problem. Nutritional factors can affect a variety of diseases, such as HL, in humans. Thus far, several studies have evaluated the association between nutrition and hearing. These studies found that the incidence of HL was increased with the lack of single micro-nutrients such as vitamins A, B, C, D and E, and zinc, magnesium, selenium, iron and iodine. Higher carbohydrate, fat, and cholesterol intake, or lower protein intake, by individuals corresponded to poorer hearing status. However, higher consumption of polyunsaturated fatty acids corresponded to better hearing status of studied subjects. In addition to malnutrition, obesity was reported as a risk factor for HL. In studies of the relationship between middle ear infection and nutrition in children, it was reported that lack of vitamins A, C and E, and zinc and iron, resulted in poorer healing status due to vulnerability to infection. These studies indicate that various nutritional factors can affect hearing. Therefore, considering that multifactorial nutritional causes are responsible, in part, for HL, provision of proper guidelines for maintaining a proper nutritional status is expected to prevent some of the causes and burden of HL.

Hearing Norton Sound: mixed methods protocol of a community randomised trial to address childhood hearing loss in rural Alaska

INTRODUCTION

Childhood hearing loss has implications for school achievement, economic outcomes and quality of life. This study will engage rural Alaska communities in research to improve the school hearing screening and referral process, partnering with stakeholders to develop a locally derived, evidence-based solution to improve timely identification and treatment of childhood hearing loss.

METHODS AND ANALYSIS

Mixed methods community randomised trial in 15 communities in the Norton Sound region of northwest Alaska. Data collection will span from April 2017 until February 2020. Qualitative and mixed methods components are described in this protocol and the community randomised trial in the companion protocol. Focus groups and community events will be held leading up to the randomised trial to obtain community perspectives on childhood hearing loss in Alaska and elicit community input during trial protocol refinement (exploratory sequential stage). Stakeholder groups, including parents, children, teachers, school administrators and community health aides, will participate, along with community leaders, tribal leaders and community members. The randomised trial will be combined with qualitative, semi-structured interviews to elicit stakeholder perspectives on the intervention (explanatory sequential stage). The five stakeholder groups described above will participate in interviews. The study will conclude with additional focus groups and community events to discuss results and provide community insight for future implementation. Concluding focus groups will include policymakers, healthcare administrators, and tribal and community leaders in addition to the stakeholder groups. Informed consent and child assent will be required. Recordings will be transcribed and deidentified, with only stakeholder group recorded. Analyses will include categorical coding as well as narrative and thematic analysis.

ETHICS AND DISSEMINATION

The Hearing Norton Sound study has been approved by the Institutional Review Boards of Alaska Area, Norton Sound, and Duke University, with trial registration on clinicaltrials.gov. Study results will be distributed with equal emphasis on scientific and community dissemination.

TRIAL REGISTRATION NUMBER

NCT03309553; Results.

Prevalence of childhood hearing impairment of different severities in urban and rural areas: a nationwide population-based study in Taiwan

OBJECTIVE

Childhood hearing impairment (CHI) is a major developmental disability, but data at the national level are limited, especially those on different severities. We conducted a study to fill this data gap.

DESIGN

A nationwide study on the basis of a reporting system.

SETTING

To provide services to disabled citizens, the Taiwanese government maintains a registry of certified cases. Using data from this registry, we estimated prevalence rates of CHI of different severities from 2004 to 2010 and made comparisons between urban and rural areas.

PARTICIPANTS

Taiwanese citizens ≤17 years old.

PRIMARY OUTCOME MEASURES

To qualify for CHI disability benefits, a child must have an unaided pure-tone better ear hearing level at 0.5, 1 and 2 kHz with an average ≥55 decibels (dB), confirmed by an otolaryngologist. The severity was classified by pure-tone better ear hearing level as mild (55-69 dB), moderate (70-89 dB) and severe (≥90 dB).

RESULTS

The registered cases under 17 years old decreased annually from 4075 in 2004 to 3533 in 2010, but changes in the prevalence rate were small, ranging from 7.62/10 000 in 2004 to 7.91/10 000 in 2006. The prevalence rates of mild CHI increased in all areas over time, but not those of moderate or severe CHI. Rural areas had higher overall prevalence rates than urban areas in all years, with rate ratios (RRs) between 1.01 and 1.09. By severity, rural areas had higher prevalence rates of mild (RRs between 1.08 and 1.25) and moderate (RRs between 1.06 and 1.21) CHI but had lower prevalence rates of severe CHI (RRs between 0.92 and 0.99).

CONCLUSION

While rural areas had higher overall prevalence rates of CHI than urban areas, the RRs decreased with CHI severity. Further studies that identify factors affecting the rural-urban difference might help the prevention of CHI.

Early childhood undernutrition increases risk of hearing loss in young adulthood in rural Nepal

Background

Prevalence of young adult hearing loss is high in low-resource societies; the reasons for this are likely complex but could involve early childhood undernutrition.

Objective

We evaluated preschool childhood stunting, wasting, and underweight as risk factors for hearing loss in young adulthood in Sarlahi District, southern Nepal.

Design

Ear health was assessed in 2006-2008 in a cohort of 2193 subjects aged 16-23 y, who as children <60 mo of age participated in a 16-mo placebo-controlled, randomized vitamin A supplementation trial from 1989 to 1991. At each of five 4-mo assessments, field staff measured children's weight, height, and mid-upper arm circumference (MUAC) and recorded validated parental history of ear discharge in the previous 7 d. Children were classified as stunted [<-2 z score height-for-age (HAZ)], underweight [<-2 z score weight-for-age (WAZ)], or wasted [<-2 z score MUAC-for-age (MUACAZ) or body mass index-for-age (BMIAZ)]. At follow-up, hearing was tested by audiometry and tympanometry, with hearing loss defined as pure-tone average >30dB in the worse ear (0.5, 1, 2, 4 kHz) and middle-ear dysfunction as abnormal tympanometric peak height (<0.3 or >1.4 mmho) or width (<50 or >110 daPa).

Results

Hearing loss, present in 5.9% (95% CI: 5.01%, 7.00%) of subjects, was associated with early childhood stunting (OR: 1.64; 95% CI: 1.10, 1.45), underweight (OR: 1.70; 95% CI: 1.18, 2.44) and wasting by BMIAZ (OR: 1.88; 95% CI: 1.19, 2.97) and MUACAZ (OR: 2.14; 95% CI: 1.47, 3.12). Abnormal tympanometry, affecting 16.6% (95% CI: 15.06%, 18.18%), was associated with underweight (OR: 1.46; 95% CI: 1.16, 1.84) and wasting by BMIAZ (OR: 1.80; 95% CI: 1.32, 2.46) and MUACAZ (OR: 1.42; 95% CI: 1.10, 1.84), but not stunting (OR: 1.18; 95% CI: 0.93, 1.49) in early childhood. Highest ORs were observed for subjects with both hearing loss and abnormal tympanometry, ranging from 1.87 to 2.24 (all lower 95% CI >1.00).

Conclusions

Early childhood undernutrition is a modifiable risk factor for early adulthood hearing loss.

Prevalência de perda auditiva em adolescentes e adultos jovens decorrentes de exposição a ruído social: meta-análise

RESUMO: A exposição a ruídos no lazer de adolescentes e jovens adultos tem chamado atenção, dada a repercussão da perda auditiva nessa população. Esse estudo propôs estimar a prevalência de perda auditiva dessa população decorrentes de exposição a ruídos sociais. Foram identificados 17 artigos para análise que atenderam aos critérios de seleção, sobre os quais se observaram informações de: delineamento, faixa etária, localização, modo de avaliação e a prevalência de perda auditiva. Nos estudos autorreferidos, a prevalência foi inferior a 2%, enquanto aqueles que realizam audiometria foi de 11,5 e de 15,8%. Concluiu-se uma heterogeneidade entre a prevalência de perda auditiva autorreferida e a mensurada por exames audiométricos na população pesquisada.

Hearing loss is associated with decreased nonverbal intelligence in rural Nepal

OBJECTIVE

To evaluate the association between adolescent and young-adult hearing loss and nonverbal intelligence in rural Nepal.

STUDY DESIGN

Cross-sectional assessment of hearing loss among a population cohort of adolescents and young adults.

SETTING

Sarlahi District, southern Nepal.

PATIENTS

Seven hundred sixty-four individuals aged 14 to 23 years.

INTERVENTION

Evaluation of hearing loss, defined by World Health Organization criteria of pure-tone average greater than 25 decibels (0.5, 1, 2, 4 kHz), unilaterally and bilaterally.

MAIN OUTCOME MEASURE

Nonverbal intelligence, as measured by the Test of Nonverbal Intelligence, 3rd Edition standardized score (mean, 100; standard deviation, 15).

RESULTS

Nonverbal intelligence scores differed between participants with normal hearing and those with bilateral (p = 0.04) but not unilateral (p = 0.74) hearing loss. Demographic and socioeconomic factors including male sex; higher caste; literacy; education level; occupation reported as student; and ownership of a bicycle, watch, and latrine were strongly associated with higher nonverbal intelligence scores (all p < 0.001). Subjects with bilateral hearing loss scored an average of 3.16 points lower (95% confidence interval, -5.56 to -0.75; p = 0.01) than subjects with normal hearing after controlling for socioeconomic factors. There was no difference in nonverbal intelligence score based on unilateral hearing loss (0.97; 95% confidence interval, -1.67 to 3.61; p = 0.47).

CONCLUSION

Nonverbal intelligence is adversely affected by bilateral hearing loss even at mild hearing loss levels. Socio economic well-being appears compromised in individuals with lower nonverbal intelligence test scores.

Prevalence of noise-induced hearing loss among woodworkers in Nepal: a pilot study

BACKGROUND

The woodworking industry represents an important cause of occupational noise-induced hearing loss (NIHL), a significant yet underappreciated problem in many developing countries.

OBJECTIVES

To describe the prevalence of occupational NIHL among woodworkers in Nepal and measure noise levels at workplaces.

METHODS

We conducted a cross-sectional study with 124 woodworkers (88 carpenters, 36 sawyers), recruited through convenience sampling from 26 workplaces. Pure-tone audiometry between the frequencies 0·5 and 8 kHz ascertained participants' hearing status, and noise readings were taken at selected workplaces.

RESULTS

In all, 31% of carpenters and 44% of sawyers met criteria for NIHL, with 7 and 17% meeting World Health Organization (WHO) criteria for hearing impairment (HI), respectively. Noise levels at various workplaces ranged from 71·2 to 93·9 dBA.

CONCLUSIONS

Woodworkers in Nepal are at risk of occupational NIHL. As the industry develops, this problem will likely become more extensive, highlighting the need for workplace interventions and additional research.

Vitamin A supplementation in preschool children and risk of hearing loss as adolescents and young adults in rural Nepal: randomised trial cohort follow-up study

OBJECTIVE

To determine whether vitamin A supplementation administered in the preschool years can lower the risk of hearing loss in adolescence and adulthood.

DESIGN

Follow-up study of adolescents and young adults who, as preschool aged children in 1989, were enrolled into a cluster randomised, double blinded, placebo controlled trial of vitamin A supplementation.

SETTING

South central, rural Nepal.

PARTICIPANTS

2378 adolescents and young adults aged 14 to 23, representing 51% of those who finished the original trial and 71% of those living in the study area in 2006.

INTERVENTIONS

Every four months for 16 months preschool children were visited at home, given an oral 200,000 IU dose of vitamin A (half dose at age 1-11 months, quarter dose at <1 month) or placebo and the parents were queried about any childhood illnesses in the previous week, including purulent discharge from the ears.

MAIN OUTCOME MEASURES

Prevalence of mild or worse hearing loss (≥ 30 dB) in the most affected ear and tympanometric measures of middle ear function (peak height, ear canal volume, and gradient).

RESULTS

During the original trial, the prevalence of middle ear infection during the preschool years did not differ between the supplement groups. By adolescence and early adulthood, a non-significant 17% reduction in hearing loss occurred among those who had periodically received vitamin A compared with placebo as preschool aged children (odds ratio 0.83, 95% confidence interval 0.62 to 1.12). Among participants with any ear discharge in early childhood, vitamin A supplementation was associated with a reduced risk of hearing loss, by 42% (0.58, 0.37 to 0.92) compared with controls, after adjusting the confidence interval for the design effect of the original trial. Abnormal tympanometric peak height of the middle ear system was less likely among participants supplemented with vitamin A in childhood.

CONCLUSION

In undernourished settings, periodic, high dose vitamin A supplementation may reduce the risk of hearing loss associated with purulent ear infections in early childhood.

Hearing impairment in otitis media with effusion: a cross-sectional study based in Pokhara, Nepal

OBJECTIVE

Otitis media with effusion (OME) is a major cause of childhood hearing impairment (HI) in the developing world, but its prevalence has never been quantified in Nepal. This study therefore set out to determine the proportion of cases of OME complicated by HI and to identify associated factors.

METHODS

This was a cross-sectional prevalence survey carried out in rural, urban and Tibetan schools in and around Pokhara, Nepal. HI was the primary outcome, and was defined as a middle-frequency pure tone average >25 dB on audiological testing. The study population was defined as children aged four years and older, attending primary school and with a diagnosis of OME.

RESULTS

One hundred and eleven schoolchildren with a combined total of 172 ears affected by OME underwent audiometric assessment. HI was most prevalent in the rural Nepali population; 27% (95%CIs 18-38%) had HI, with a mean hearing loss of 22 dB (15-25 dB). In the Tibetan population, 16% (8-29%) had HI, with a mean loss of 17 dB (12-22 dB). The urban Nepali population had the least HI; 4% (1-13%) were affected, with a mean loss of 16 dB (15-19 dB). The difference in prevalence between the urban and rural Nepali populations was statistically significant (p>0.05). Logistic regression analysis did not identify any associated factors.

CONCLUSIONS

HI is a common complication of OME in Nepal. There is hitherto-unreported variation between populations in the number of cases of OME complicated by HI. This study identified higher rates of morbidity amongst rural populations but was unable to identify associated factors.