Epidemiological characteristics of mass hysteria in children and adolescents:a meta-analysis

Objective To explore the epidemiologic characteristics of mass hysteria(MH)among children and adolescents.Methods Studies on MH from 2000 through 2013 were obtained though literature review and analyzed comparatively.We used descriptive epidemiology and meta-analysis to assess attack rates(ARs)of MH and the ARs were calculated by weighting the accumulated means with the number of the sample studied.Results Totally 95 studies(N=118939) reporting ARs of MH in children and teenagers were included in the study,of which,64 were categorized as with high or moderate methodological quality.For the 95 studies,the pooled MH AR was 14.6%(8721 MH cases in 118939 subjects aged 6-19 years)(95%confidence interval95%CI=0.117-0.181,P<0.0001)and the reported ARs ranged from 11.7%to 25.3%,4.8%to 25.8%,and 7.0%to 23.9%for the studies conducted at different years,populations,and regions.The included studies reported higher ARs in the girls than in the boys,with a pooled odds ratio of 2.9(95%CI=2.1-4.1,P<0.0001).Conclusion The findings of this research suggest that there may be some differences in the epidemiological characteristics of MH among children and adolescents and the attack rate of MH in the populations may be influenced by gender,nationality,education,socioeconomic condition,regional disparity,triggering factors,and the index case.