Screening, rubella vaccination, and childhood hearing impairment in Taiwan

Childhood hearing impairment (CHI) is a major developmental disability, but data at the national level are limited, especially those on the changes in the prevalence over time. In Taiwan, the government began to certify disabled residents for providing various services in 1980 and maintains a registry of certified cases, which provides a rare opportunity for studying the trends of CHI prevalence. Using the registry data, we estimated the prevalence of CHI by age and severity and explored factors affecting its changes over time. From 2000 to 2011, the registered cases under 17 years old ranged from 3427 to 4075. The overall prevalence increased from 2000 to 2006, but then decreased till 2011. While the prevalence of mild CHI increased over the years, such a pattern was not observed in moderate or severe CHI. In general, the overall prevalence increased over the years in the age groups <3 years, 3-5 years, and 6-11 years (p<. 0.01), and the largest increase was observed in the age group <3 years, particularly after the promotion of screening by the government in 2003. The decrease after 2006 was mainly attributable to decreases in the age groups 12-14 (with a decreasing trend from 2001, p<. 0.01) and 15-17 years (with a decreasing trend from 2004, p<. 0.01). The timing was related to the implementation of a nationwide rubella vaccination program. Similar decreases had been observed in countries with rubella vaccination programs.