OBJECTIVETo study the epidemiological features of tic disorders (TD) among schoolchildren in Wenzhou area.

METHODSStratified cluster sampling was carried out to investigate TD in 9742 schoolchildren aged 7 to 16 years old in Wenzhou.

RESULTSThe average prevalence rate of TD among school-age children was 104/10 000 (166/10 000 for males, 29/10 000 for females). There was a significantly higher prevalence rate for males than that for females (chi(2) = 43.96, P < 0.001, prevalence ratio = 5.7, prevalence ratio 95% CI: 3.20 - 10.30). The prevalence rates of clinical subtypes in males was significantly higher than that of females while pupils was significantly higher than that in high school students (chi(2) = 11.33, P < 0.01, prevalence ratio = 2.2, prevalence ratio 95% CI: 1.37 - 3.43). Prevalence rate of transient tic disorders (TTD), chronic motor vocal tic disorder (CMVTD), tourette syndrome (TS) were 34/10 000, 27/10 000 and 43/10 000 respectively with the highest among 9-10 years old group. The mean onset age of TD was 8.5 +/- 2.8 years. The peak of onset was among 6-10 year olds. The rate of delayed diagnosis of the disorders was 69.3% and the median in delayed diagnosis was 1.0 year.

CONCLUSIONTD is a common disease with high rate of misdiagnoses among schoolchildren in Wenzhou area. Physicians and population should be trained to identify the syndromes and to practice correct diagnosis and effective treatment as early as possible.