To estimate the prevalence of hearing impairment in Mahabubnagar district, Telangana state, India.
A population-based prevalence survey of hearing impairment was undertaken in 2014. Fifty-one clusters of 80 people aged 6 months and older were selected using probability-proportionate-to-size sampling. A two-stage hearing screening was conducted using otoacoustic emissions on all participants followed by pure-tone audiometry on those aged 4 years and older who failed otoacoustic emissions. Cases of hearing impairment were defined using the World Health Organization definition of disabling hearing impairment: a pure-tone average of thresholds at 500, 1000, 2000, and 4000 Hz of ≥41 dB HL for adults and ≥31 dB HL for children based on the better ear. Possible causes of hearing impairment were ascertained by a certified audiologist. Reported hearing difficulties were also measured in this survey and compared with audiometry results.
Three thousand five hundred seventy-three people were examined (response rate 87%), of whom 52% were female. The prevalence of disabling hearing impairment was 4.5% [95% confidence interval (CI) = 3.8 to 5.3). Disabling hearing impairment prevalence increased with age from 0.4% in those aged 4 to 17 years (95% CI = 0.2 to 1.1) to 34.7% (95% CI = 28.7 to 41.1) in those aged older than 65 years. No difference in prevalence was seen by sex. Ear examination suggested that the possible cause of disabling hearing impairment was chronic suppurative otitis media for 6.9% of cases and dry perforation for 5.6% cases. For the vast majority of people with disabling hearing impairment, a possible cause could not be established. The overall prevalence of reported or proxy reported hearing impairment was 2.6% (95% CI = 2.0 to 3.4), and this ranged from 0.6% (95% CI = 0.08 to 4.4) in those aged 0 to 3 years to 14.4% (95% CI = 9.8 to 20.7) in those aged older than 65 years.
Disabling hearing impairment in Telangana State is common, affecting approximately 1 in 23 people overall and a third of people aged older than 65 years. These findings suggest that there are a substantial number of individuals with hearing impairment who could potentially benefit from improved access to low-cost interventions.