Objective  The frequency of health care workers' witness of violent injuries to colleagues and adverse effects resulting from such violence were investigated in order to provide a reference basis for making the relevant policies and measures to prevent the occurrence of violence.

  Methods  Taking the hospitals in Shandong, Henan, and Guizhou provinces as the study objects, 1 588 health care workers in 43 hospitals were surveyed by the multi-stage random stratified sampling.

  Results  Totally 54.0% surveyed subjects had witnessed at least one violent injury event to his/her colleagues in previous year, while 16.4% had witnessed at least 3 events. Thus, they became more cautious in their work(72.2%), had decline in work enthusiasm (71.6%), occurred depression, anxiety, anger and other bad emotions (61.0%) and wanted to change job (52.6%). Logistic regression analysis showed that: (1) Compared with the personnel in the first-class hospital and administrative logistics staff, the staff in the third-class hospital(OR = 1.457, P = 0.020) or the second-class hospital(OR = 1.569, P = 0.009), and medical doctors(OR = 2.283, P < 0.001) or nurses (OR = 1.873, P = 0.007) had a higher risk of witnessing violent incidents; compared with those with senior professional titles, those with lower professional titles (OR = 0.525, P = 0.021) had less risk of witnessing violent trauma. (2) Compared with administrative logistics staff, medical doctors (OR = 2.903, P < 0.001), nurses (OR = 3.224, P < 0.001) or medical technicians (OR = 2.742, P < 0.001) were more likely to have negative cognition of doctor-patient relationship and their children's willingness to practice medicine; compared with senior professional titles or witnessed violent incidents, hospital practitioners with lower professional titles (OR= 0.487, P = 0.007) and hospital practitioners without witnesses of violent incidents (OR = 0.410, P < 0.001) had less risk of negative cognition.

  Conclusions  The overall frequency of witnessing violence by medical staffs was high, which had a negative impact on their psychology. The professional identity and security of the medical staffs were low.