National incidence of joint dislocation in China: a retrospective survey of 512,187 individuals

BACKGROUND: Joint dislocations significantly impact public health. However, a comprehensive study on the incidence, distribution, and risk factors for joint dislocations in China is lacking. We conducted the China National Joint Dislocation Study, which is a part of the China National Fracture Study conducted to obtain the national incidence and risk factors for traumatic fractures, and to investigate the incidence and risk factors for joint dislocations. METHODS: For this national retrospective epidemiological study, 512,187 participants were recruited using stratified random sampling and probability-proportional-to-size method from January 19 to May 16, 2015. Participants who sustained joint dislocations of the trunk, arms, or legs (skull, sternum, and ribs being excluded) in 2014 were personally interviewed to obtain data on age, educational background, ethnic origin, occupation, geographic region, and urbanization degree. The joint-dislocation incidence was calculated based on age, sex, body site, and demographic factors. The risk factors for different groups were examined using multiple logistic regression. RESULTS: One hundred and nineteen participants sustained 121 joint dislocations in 2014. The population-weighted incidence rate of joint dislocations of the trunk, arms, or legs was 0.22 (95% confidence interval [CI]: 0.16, 0.27) per 1000 population in 2014 (men, 0.27 [0.20, 0.34]; women, 0.16 [0.10, 0.23]). For all ages, previous dislocation history (male: OR 42.33, 95% confidence interval [CI]: 12.03–148.90; female: OR 54.43, 95% CI: 17.37–170.50) and alcohol consumption (male: OR 3.50, 95% CI: 1.49–8.22; female: OR 2.65, 95% CI: 1.08–6.50) were risk factors for joint dislocation. Sleeping less than 7 h/day was a risk factor for men. Compared with children, women aged ≥15 years (female 15–64 years: OR 0.16, 95% CI: 0.04–0.61; female ≥65 years: OR 0.06, 95% CI: 0.01–0.41) were less likely to sustain joint dislocations. Women with more than three children were at higher dislocation risk than women without children (OR 6.92, 95% CI: 1.18–40.78). CONCLUSIONS: The up-to-date data on joint dislocation incidence, distribution, and risk factors can be used as a reference for national healthcare, prevention, and management in China. Specific strategies for decreasing alcohol consumption and encouraging adequate sleeping hours should be developed to prevent or reduce dislocation incidents. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR-EPR-15005878.