Community health workers and mHealth systems for hearing screening in rural Nicaraguan schoolchildren

Abstract

Background: We aimed to investigate the effectiveness of using minimally trained community health workers (CHW) to screen schoolchildren in rural Nicaragua for hearing loss using a tablet-based audiometric system integrated with asynchronous telehealth evaluations and mobile health (mHealth) appointment reminders.

Methods: A population-based survey was conducted using community health workers (CHWs) to perform tablet-based audiometry, asynchronous telehealth evaluations, and mHealth reminders to screen 3398 school children (7-9 years of age) in 92 rural Nicaraguan communities. The accuracy of screening, test duration, testing efficiency, telehealth data validity, and compliance with recommended clinic visits were analyzed.

Results: Minimally trained CHWs successfully screened children within remote rural schools with automated audiometry (test duration = 5.8 minutes) followed by manual audiometry if needed (test duration = 4.3 minutes) with an estimated manual audiometry validity of 98.5% based on a review of convergence patterns. For children who were referred based on audiometry, the otoscopy and tympanometry obtained during telehealth evaluations were high quality (as reviewed by 3 experts) in 44.6% and 80.1% of ears, respectively. A combination of automated short message service (SMS) text messages and voice reminders resulted in a follow-up compliance of 75.2%. No families responded to SMS messages alone.

Conclusions: Tablet-based hearing screening administered by minimally trained CHWs is feasible and effective in low- and middle-income countries. Manual audiometry was as efficient as automated audiometry in this setting. The physical exam tasks of otoscopy and tympanometry require additional training. Mobile phone messages improve compliance for confirmatory audiometry, but the utility of SMS messaging alone is unclear in this population.

Figure 1

Transportation of portable audiometric equipment to remote testing sites: A) Complete tablet-based audiometric system with WAHTS mounted on motorcycle for transport. B) Student completing tablet-based automated audiometry with WAHTS headset. C) Community Health Workers en route to remote mountainous study site.

Figure 2

Flowchart of audiometric screening protocol with number of participants at each stage. *Aborted automated audiometric due to difficulty with testing or behavioral problems, **No detectable hearing loss at screened frequencies in school (1000, 2000, and 4000 Hz) – children with hearing loss outside of this range were not included in this result.

Figure 3

Geographic distribution of testing sites in the Department of Jinotega in northern Nicaragua.