Aims The association between bullying and mental health outcomes is well recognized in many countries, but there is little evidence from China. This study aimed to investigate whether there is an association between being bullied and psychosomatic well-being among Chinese middle school children.

Methods This cross-sectional survey study was conducted in 12-15-year-olds in Zhejiang, Henan and Chongqing provinces, representing Eastern Central and Western regions from May to September, 2018. It included two urban and two rural middle schools in each province, so 12 schools in total. Classes were randomly chosen to achieve roughly the same sample size in each year group in each province. A self-completion questionnaire was completed by the students in the classroom setting and included: traditional bullying, cyberbullying, and classic psychosomatic symptoms of headache, abdominal pain and sleep problems. Data analyses were performed with SPSS 24.0.

Results There were 3774 completed questionnaires, and the mean age was 13.58 (SD 0.87). 567(15%) stated they had experienced only traditional bullying, 520(14%) only cyberbullying, and 645(17%) both. The commonest forms of traditional bullying were verbal bullying experienced by 1034(27.6%) and rumour-spreading experienced by 540(14.4%). Commonest forms of cyberbullying were being teased online, 703(18.6%) and being excluded online, 690(18.5%). 491(13.3%) reported they often had headache, 607(16.5%) abdominal pain, and 597(16.1%) sleep problems. After adjusting for confounders, we found that traditional-cyber victims (adjusted OR 1.8, 95% CI 1.4-2.1), only-traditional victims (1.4, 1.1-1.7), only-cyber victims (1.6, 1.3-2.0) were more likely to have headache. Traditional-cyber victims (adjusted OR 1.8, 95% CI 1.5-2.2), only-traditional victims (1.3, 1.0-1.5), only-cyber victims (1.4, 1.1-1.7) were more likely to have abdominal pain. Traditional-cyber victims (adjusted OR 2.0, 95% CI 1.7-2.5), only-cyber victims (1.4, 1.2-1.8) were more likely to have sleep problems.

Conclusion The prevalence of bullying victims is substantial among Chinese adolescents, and is associated with psychosomatic conditions. Measures to reduce bullying are needed in Chinese schools. There needs to be increased awareness of the harm caused by bullying.