Classification of childhood hearing impairment: implications for rehabilitation in developing countries

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.

Health Disparities by Type of Disability: Health Examination Results of Adults (18-64 Years) with Disabilities in Shanghai, China

AIMS

There have been few studies on the disparities within the population with disabilities, especially in China. The aim of this study was to evaluate the differences in some health conditions among people with different types of disabilities in Shanghai.

METHODS

This study was conducted using data from the Shanghai Disabled Persons' Rehabilitation Comprehensive Information Platform. The records of 31,082 persons with disabilities who had undergone professional health examination were analyzed, and the prevalence and number of five diseases and five risk factors were examined. Logistic regression was used to explore disparities from two perspectives: 1) basic differences, unadjusted for other factors, and 2) differences after adjusting for key demographic covariates. A p-value < 0.05 was considered significant.

RESULTS

Individuals with visual disability had a high rate of refractive error (60.0%), and averaged 1.75 diseases of interest, which was the highest value among all disability types. The mean number of risk factors we measured was greatest (1.96) in the population with mental disability. There were significant differences (p < 0.05) between the hearing and speech impairment group and the other groups with respect to most health outcomes, except chronic pharyngitis, hepatic cysts, and high blood pressure.

CONCLUSION

Significant differences of selected health outcomes between groups with different types of disabilities remained after controlling for key demographic indicators. Further research is needed to explore the relationships between health conditions and disability types.

The risk of hearing loss in a population with a high prevalence of chronic suppurative otitis media

BACKGROUND

Chronic suppurative otitis media (CSOM) affects 65-330 million people in the developing part of the world and develops in early childhood. Knowledge of the long-term effects on hearing is scarce. Hearing loss (HL) can cause reduced ability to communicate, impair language development and academic skills.

OBJECTIVE

To estimate the prevalence of HL in a population with a high-risk of CSOM and to identify the risk of permanent hearing loss from CSOM.

METHODS

Ten and 15 years follow-up of two Greenlandic population-based children cohorts. Participants underwent otologic examination and audiometric evaluation. HL was defined using both the American Speech-Language-Hearing Association's (ASHA) and the World Health Organizations's (WHO) definition. Risk factors for HL were analyzed, using binomial logistic regression analysis.

RESULTS

A total of 438 individuals aged 11-24 years participated. Using the ASHA definition of HL the prevalence was 50% (95% CI 45.3-54.7). Using the WHO definition of HL the prevalence was 2.5% (95% CI 1.1-3.98). CSOM was the main cause of HL. Co-existing CSOM (OR 16.7, 95% CI 8.29-33.65), spontaneous healing from CSOM (OR 3.75, 95% CI 1.62-8.67), and male gender (OR 2.2, 95% CI 1.28-3.78) were associated with HL. Ninety-one percent of children with CSOM developed a permanent hearing loss >15dBHL.

CONCLUSION

CSOM was strongly associated with permanent hearing loss. CSOM was the main reason for HL in this population. The WHO definition of hearing loss is likely to underestimate the burden of hearing loss among children and adolescents in developing countries with a high prevalence of CSOM.

Hearing screening for school children: utility of noise-cancelling headphones

BACKGROUND

Excessive ambient noise in school settings is a major concern for school hearing screening as it typically masks pure tone test stimuli (particularly 500 Hz and below). This results in false positive findings and subsequent unnecessary follow-up. With advances in technology, noise-cancelling headphones have been developed that reduce low frequency noise by superimposing an anti-phase signal onto the primary noise. This research study examined the utility of noise-cancelling headphone technology in a school hearing screening environment.

METHODS

The present study compared the audiometric screening results obtained from two air-conduction transducers-Sennheiser PXC450 noise-cancelling circumaural headphones (NC headphones) and conventional TDH-39 supra-aural earphones. Pure-tone hearing screening results (500 Hz to 4000 Hz, at 30 dB HL and 25 dB HL) were obtained from 232 school children, aged 6 to 8 years, in four Hong Kong primary schools.

RESULTS

Screening outcomes revealed significant differences in referral rates between TDH-39 earphones and NC headphones for both 30 dB HL and 25 dB HL criteria, regardless of the inclusion or exclusion of 500 Hz results. The kappa observed agreement (OA) showed that at both screening intensities, the transducers' referral agreement value for the 500 Hz inclusion group was smaller than for the 500 Hz exclusion group. Individual frequency analysis showed that the two transducers screened similarly at 1000 Hz and 2000 Hz at 25 dB HL, as well as at both 30 dB HL and 25 dB HL screening levels for 4000 Hz. Statistically significant differences were found for 500 Hz at 30 dB HL and at 25 dB HL, and for 1000 Hz and 2000 Hz at 30 dB HL. OA for individual frequencies showed weaker intra-frequency agreement between the two transducers at 500 Hz at both intensity criterion levels than at higher frequencies.

CONCLUSIONS

NC headphones screening results differed from those obtained from TDH-39 earphones, with lower referral rates at 500 Hz, particularly at the 25 dB HL criterion level. Therefore, NC headphones may be able to operate at lower screening intensities and subsequently increase pure-tone screening test sensitivity, without compromising specificity. NC headphones show some promise as possible replacements for conventional earphones in school hearing screening programs.

Functional performance among children with cochlear implants and additional disabilities

OBJECTIVE

To assess daily functional skills among young cochlear implant (CI) recipients with additional disabilities.

METHODS

Children with CI and developmental disabilities and a hearing control group containing similar ages and similar disabilities were enrolled in a cross-sectional study of language and functional skills. Daily functional skills were measured using the Pediatric Evaluation of Disability Inventory (PEDI), which provides standard and scaled scores in Self-Care, Mobility, and Social Functioning domains. Language was assessed using the Preschool Language Scales, 4th edition which provides standard scores and age equivalents.

RESULTS

Fourteen children with CIs and seven hearing controls were included in this analysis. Most children in this study (90.5%) had cognitive disabilities and 57% had motor disabilities. Compared with the hearing controls, children with CIs were less likely to have functional independence in any PEDI domain. Children with CI had significantly lower median social functioning standard scores compared with controls (17.3 vs. 27.5, P = 0.009). After controlling for nonverbal cognitive abilities and language level, the difference was no longer significant (19.1 vs. 24, P = 0.3). Among children with CI, age at implant and duration with device were not associated (P > 0.4) with PEDI scores.

DISCUSSION

Although children with CI and developmental disabilities had similar functional skills as hearing children with similar disabilities regarding the PEDI domains of Self-Care and Mobility, they had lower Social Function standard scores. This lower social functioning among children with implants may be related to lower language levels and possible language deficits seen in the CI group. Regular assessments of functional abilities coupled with language abilities are essential in providing every child with the opportunity for maximizing the potential for independence.

Participation and environmental aspects in education and the ICF and the ICF-CY: findings from a systematic literature review

BACKGROUND

This paper presents findings from a systematic review of the literature related to participation and the ICF/ICF-CY in educational research.

OBJECTIVES

To analyse how and investigate the application of participation in educational research. Specifically, how participation is related to the environmental dimensions availability, accessibility, affordability, accommodability and acceptability.

METHODS

A systematic literature review using database keyword searches and refinement protocols using inclusion and exclusion criteria at abstract, full-text and extraction.

RESULTS

Four hundred and twenty-one initial works were found. Twenty-three met the inclusion criteria. Availability and accommodations are the most investigated dimensions. Operationalization of participation is not always consistent with definitions used.

CONCLUSION

Research is developing a holistic approach to investigating participation as, although all papers reference at least one environmental dimension, only four of the 11 empirical works reviewed present a fully balanced approach when theorizing and operationalizing participation; hopefully this balanced approach will continue and influence educational policy and school practice.

Childhood disability in low- and middle-income countries: overview of screening, prevention, services, legislation, and epidemiology

BACKGROUND

Childhood disability affects millions of children around the world, most of whom are in low- and middle-income countries. Despite the large burden on child development, family life, and economics, research in the area of childhood disability is woefully inadequate, especially from low- and middle-income countries.

OBJECTIVE

The objective of this review was to generate information about current knowledge on childhood disability in low- and middle-income countries and identify gaps to guide future research.

METHODS

Electronic databases (PubMed, Embase, PsycInfo) were searched by using specific search terms related to childhood disability in developing countries. The Cochrane Library was also searched to identify any similar reviews. Whole texts of articles that met study criteria were scrutinized for information regarding research method, screening tools, epidemiology, disability-related services, legislation, and prevention and promotion activities. Quantitative and qualitative information was collated, and frequency distributions of research parameters were generated.

RESULTS

Eighty articles were included in the review (41 from low-income countries). Almost 60% of the studies were cross-sectional; case-control, cohort, and randomized, controlled trials accounted for only 15% of the studies. Of the 80 studies, 66 focused on epidemiologic research. Hearing (26%) and intellectual (26%) disabilities were the commonly studied conditions. The Ten Questionnaire was the most commonly used screening tool. Information on specific interventions, service utilization, and legislation was lacking, and study quality generally was inadequate. Data on outcomes of morbidities, including delivery complications and neonatal and early childhood illness, is particularly lacking.

CONCLUSIONS

With this review we identified potential gaps in knowledge, especially in the areas of intervention, service utilization, and legislation. Even epidemiologic research was of inadequate quality, and research was lacking on conditions other than hearing and intellectual disabilities. Future researchers should not only address these gaps in current knowledge but also take steps to translate their research into public health policy changes that would affect the lives of children with disabilities in low- and middle-income countries.