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

Abstract

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.

Keywords:

• Demographics/epidemiology
• adult or general hearing screening
• aging
• hearing aids

Acknowledgments

This research has been made possible through the hard work of many individuals and organisations. Firstly, we thank the study participants for their generous time in taking part in the study. Secondly, we recognise the efforts of the village leaders from Malawi for their assistance in coordinating the survey. We also thank hearX and colleagues for their support in the use of hearTest and integration of ODK with hearTest. Finally, we thank colleagues from the International Centre for Evidence in Disability for their input in to the survey protocol development. Electronic data solutions were provided by LSHTM Open Research Kits (odk.lshtm.ac.uk).

Disclosure statement

The fifth author (D.W.) is a scientific advisor to the hearX group. His relationship includes equity and consulting. The other authors report no conflict of interest.

Additional information

Funding

This study was funded by CBM International and the Academy of Medical Science Newton Advanced Fellowship

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