Assessment of Central Auditory Processing in Children Using a Novel Tablet-Based Platform: Application for Low- and Middle-Income Countries.

OBJECTIVE: Evaluate whether a portable, tablet-based central auditory processing (CAP) test system using native language training videos and administered by minimally trained community health workers can produce CAP results comparable to previously published norms. Our secondary aim was to determine subject parameters that influence test results. STUDY DESIGN: Cross-sectional study. SETTING: Community-based settings in Chontales, Nicaragua, New Hampshire, and Florida. PATIENTS: English- and/or Spanish-speaking children and adolescents (n = 245; average age, 12.20 yr; range, 6-18 yr). MAIN OUTCOME MEASURES: Completion of the following tests with responses comparable to published norms: Pure-tone average (PTA), gap detection threshold (GDT), fixed-level frequency threshold, masking level difference (MLD), Hearing in Noise Test (HINT), Dichotic Digits Test (DDT), and Frequency Pattern Recognition (FPR) test. RESULTS: GDT, HINT, and DDT had comparable results to previously published normative values. MLD and FPR results differed compared with previously published normative values. Most CAP tests (MLD, GDT, HINT) results were independent of age and PTA (p = 0.1-0.9). However, DDT was associated with age and PTA (p < 0.0001). CONCLUSIONS: Pediatric CAP testing can be successfully completed in remote low- and middle- income country environments using a tablet-based platform without the presence of an audiologist. Performance on DDT improved with age but deteriorated with hearing loss. Further investigation is warranted to assess the variability of FPR.

Test-Retest repeatability of automated threshold audiometry in Nicaraguan schoolchildren.

OBJECTIVE: Automated threshold audiometry (ATA) could increase access to paediatric hearing assessment in low- and middle-income countries, but few studies have evaluated test-retest repeatability of ATA in children. This study aims to analyse test-retest repeatability of ATA and to identify factors that affect the reliability of this method. DESIGN: ATA was performed twice in a cohort of Nicaraguan schoolchildren. During testing, the proportion of responses occurring in the absence of a stimulus was measured by calculating a stimulus response false positive rate (SRFP). Absolute test-retest repeatability was determined between the two trials, as well as the impact of age, gender, ambient noise, head circumference, and SRFP on these results. STUDY SAMPLE: 807 children were randomly selected from 35 schools in northern Nicaragua. RESULTS: Across all frequencies, the absolute value of the difference between measurements was 5.5 ± 7.8 dB. 89.6% of test-retest differences were within 10 dB. Intra-class correlation coefficients between the two measurements showed that lower SRFP was associated with improved repeatability. No effect of age, gender, or ambient noise was found. CONCLUSIONS: ATA produced moderate test-retest repeatability in Nicaraguan schoolchildren. Participant testing behaviours, such as delayed or otherwise inappropriate response patterns, significantly impacts the repeatability of these measurements.

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.