Ten-year trends in the incidence of microtia: a nationwide population-based study from Taiwan

Few studies have explored population-based incidence rates of microtia using nationwide data. The aim of this study was to analyze the 10-year secular trends in the incidence of microtia and/or anotia in Taiwan from 2008 to 2017 using nationwide population-based data. Patient data were retrieved from Taiwan’s National Health Insurance Dataset, after identifying 1152 children aged ≤ 1 year with a first-time diagnosis of microtia or anotia between January 2008 and December 2017. The annual microtia–anotia incidence rate was the sum of new microtia–anotia cases in a year divided by total infant population in the year. Furthermore, we used the annual percent change (APC) to study the secular trend in microtia–anotia incidence rate. The annual incidence rate of microtia–anotia averaged across the 10-year period was 57.7 per 100,000 infants (standard deviation = 8.6). The annual incidence rates of microtia and anotia were 53.3 and 4.4 per 100,000 infants, respectively, during this period. Furthermore, female infants had a higher incidence than males (63.3 vs. 52.4 per 100,000). The incidence of microtia–anotia gradually decreased between 2008 and 2017 with an APC of − 5.64% (95% CI − 9.31 ~ − 1.18%, p = 0.004). Since 2011, females had a significantly higher annual incidence rate of microtia–anotia than males. The incidence of microtia–anotia was 57.7 per 100,000 infants in Taiwan, which declined during the study period 2008–2017. The female-to-male incidence ratio was 1.21:1.