[Prevalence and etiology of people with hearing impairment in China]

To investigate the prevalence and etiology of people with hearing disability in China and to provide evidence for development of related prevention and treatment strategies.Using the statistics and inference from data of the Second China National Sample Survey on Disability.27.80 million people were diagnosed with hearing disability, including 20.04 million with pure disability. The overall prevalence was 2.11% including 'single disability' as 1.52% (accounting for 72.08%) and the rate was 11.04% among the elderly(accounting for 73.57%). The prevalence of hearing disability was higher in males than in females as well as higher in the rural than in the urban. Sufferers were mainly engaging in agriculture with poor education background. Among all the people with hearing disability, Grade III and IV was accounted for 73.42% but among the elderly, they were accounted for 79.13%. Grade I and II was accounted for 67.36% among children aged four to six and 83.90% in children aged below three. Speech disabilities were more than 70% in aged below six. The whole etiology contains presbycusis, unknown causation and tympanitis with primary causes as heredity, pregnant virus infection, neonatal asphyxiation, drug-induced deafness, premature delivery and low birth avoirdupois, other than unknown deaf among the 0-6 year olds. However, the primary causation would include presbycusis, tympanitis, sickness, noise/detonation and drug-induced deafness for the elderly.Active prevention on presbycusis with emphasis on prevention and cure to rural population was important in reducing the venture of hearing disability. Related consultation on genetic factors was another measure to be taken to prevent hearing disability developed in the newborns.