Prevalence of severe-profound hearing loss in South Korea: a nationwide population-based study to analyse a 10-year trend (2006-2015)

Abstract

To estimate prevalence of severe-profound hearing loss (HL) in South Korea, and analyse a 10-year trend of HL according to age, sex, and region by using a nationwide population-based database. Retrospective review from Korean National Health Insurance Service from 2006 to 2015. The degree of severe-profound HL was classified into six grades, based mostly on HL worse than 60 dB HL for both ears. Absolute number of HL was the highest in 2011 (0.25 million; males, 0.14 million; females, 0.11 million); it decreased gradually until 2015. Total HL prevalence was the highest in 2010 (0.5%; 251,954), and decreased annually to 2015 (0.46%; 237,272). The trend of HL prevalence showed a gradual decrease from 2010 to 2015. Prevalence of severe-profound HL was always higher in the male population (1.19 times higher than female in 2015). Prevalence of HL was higher in rural areas than in urban areas (1.4 times higher in 2015). Number of severe-profound HL in South Korea decreased gradually in all age groups annually, even though some older age groups had the highest peak in 2010-2011. Prevalence of severe-profound HL decreases gradually in all age groups annually in South Korea, although the absolute number of HL cases increases rapidly among those aged over 80 years.

Figure 1

The status of severe-profound hearing loss (HL) in South Korea from 2006 to 2015. (A) The total population of South Korea continues to increase from 48.6 million to 51.8 million. (B) Population with severe-profound HL. (C) Sex-wise distribution of the population with severe-profound HL. Males have more severe-profound HL than do females. (D) The percentage of severe-profound HL using a nationwide population-based study to analyse a 10-year trend in hearing impairment. Total HL percentage of 2010 is 0.5%, which is the highest, and it decreases to 0.46% in 2015. The trend of HL percentage shows a gradual decrease from 2010 to 2015. The percentage of severe-profound HL is always higher in the male population than in the female population.

Figure 2

The total number of patients with severe-profound hearing loss (HL) in South Korea determined using a nationwide population-based study to analyse a 10-year trend in hearing impairment. (A) The number is the highest in 2011 (0.25 million individuals), and decreases gradually until 2015. (B) From 2006 to 2015, the prevalence of 1st grade HL increased from 1.91% to 3.04%; 2nd grade HL decreased from 24.5% to 18.1%; 3rd grade HL decreased from 17.89% to 16.75%; 4th grade HL increased from 19.56% to 21.77%; 5th grade HL increased from 18.6% to 24.63%; and 6th grade HL decreased from 17.54% to 15.71%. ¹both-side HL ≥ 90 dB HL and speech disorder, ²both-side HL ≥ 90 dB HL, ³both-side HL ≥ 80 dB HL, ⁴both-side HL ≥ 70 dB HL, ⁵both-side HL ≥ 60 dB HL, ⁶worse-side HL ≥ 80 dB HL and other-side HL ≥ 40 dB HL.

Figure 3

Number of patients with severe-profound hearing loss (HL) in the male and female population determined using a nationwide population-based study to analyse a 10-year trend in hearing impairment. (A) The prevalence in the male is the highest in 2011 (0.14 million individuals), and decreases gradually until 2015. (B) The prevalence in the female is the highest in 2011 (0.11 million individuals), and decreases gradually until 2015. ¹both-side HL ≥ 90 dB HL and speech disorder, ²both-side HL ≥ 90 dB HL, ³both-side HL ≥ 80 dB HL, ⁴both-side HL ≥ 70 dB HL, ⁵both-side HL ≥ 60 dB HL, ⁶worse-side HL ≥ 80 dB HL and other-side HL ≥ 40 dB HL.

Figure 4

The regional distribution of age-standardized prevalence of severe-profound hearing loss (HL) in South Korea. Higher HL prevalence is shown in rural areas (eight latter areas) than in urban areas (nine initial cities or towns). Age-standardized prevalence of severe-profound HL is the highest in Jeonnam province, followed by Joenbuk province. The lowest prevalence is in Seoul, the capital of South Korea. Average of age-standardized prevalence value is 6.11 in rural areas and 4.39 in urban areas. ¹both-side HL ≥ 90 dB HL and speech disorder, ²both-side HL ≥ 90 dB HL, ³both-side HL ≥ 80 dB HL, ⁴both-side HL ≥ 70 dB HL, ⁵both-side HL ≥ 60 dB HL, ⁶worse-side HL ≥ 80 dB HL and other-side HL ≥ 40 dB HL. For more details, see the supplementary file that is uploaded online.

Figure 5

Number of individuals with severe-profound hearing loss (HL) in South Korea determined using a nationwide population-based study to analyse a 10-year trend according to age groups. In HL patients younger than 50 years, the number of HL cases decrease annually in all age groups (<10, 10 s, 20 s, 30 s, and 40 s). Among those in the 50 s, the number of HL cases is the highest at 37,497 in 2011, decreasing annually thereafter. Among those in the 60 s, the number of HL cases is the highest at 56,528 in 2010, decreasing annually thereafter. Among those in the 70 s, the number of HL cases is the highest at 73,188 in 2012, decreasing annually thereafter. However, the number of HL cases increases rapidly among those aged over 80 years (18,833 in 2006 to 58,738 in 2015).

Figure 6

Prevalence of severe-profound hearing loss (HL) in South Korea determined using a nationwide population-based study to analyse a 10-year trend according to age groups. From the youngest group to the oldest group, the prevalence of severe-profound HL increases exponentially from 0.033% to 4.168%. In HL patients younger than 60 years, the prevalence of HL decreases annually in all age groups (<10, 10 s, 20 s, 30 s, 40 s, and 50 s). Among those in the 60 s, the prevalence of HL is the highest at 1.368% in 2010, decreasing annually thereafter. Among those in the 70 s, the prevalence of HL is the highest at 2.739% in 2010, decreasing annually thereafter. Among those in the 80 s, the prevalence of HL is the highest at 4.841% in 2011, decreasing annually thereafter, although the absolute number of HL cases increases rapidly among those aged over 80 years. Thus, the prevalence of severe-profound HL decreases gradually in all age groups annually in South Korea.