Epidemiological characteristics and influencing factors of scoliosis in adolescents aged 7 to 18 years in Shanghai, China: a population-based study on prevention and control strategies

Background Adolescent scoliosis is a common spinal health problem that can lead to pain, functional limitation, psychological burden, and avoidable health-care costs when not identified early. Although school-based screening is widely recommended in China, local epidemiological evidence from large urban communities remains limited. This study aimed to investigate the epidemiological characteristics of scoliosis and identify associated factors among adolescents aged 7 to 18 years in Shanghai, China, in order to inform prevention and control strategies. Methods A population-based school screening study was conducted in Fenglin Subdistrict, Xuhui District, Shanghai, from June 2024 to May 2025. A total of 7979 adolescents from three primary schools, four junior high schools, and one senior high school were included. Screening followed a standardized three-step protocol comprising visual inspection, scoliometer measurement, and confirmatory radiography when indicated. A structured questionnaire collected information on demographics, parental history of scoliosis, nutritional status, schoolbag characteristics, sedentary time, physical activity, and exercise type. Chi-square tests and binary logistic regression were used to examine factors associated with scoliosis. Results Among 7979 adolescents, 255 scoliosis cases were identified, corresponding to an overall detection rate of 3.20%. Girls had a higher detection rate than boys (3.91% vs 2.56%), and detection increased from 1.58% in the 7 to 9 year age group to 4.18% in the 13 to 18 year age group. In multivariable analysis, female sex (OR 1.853, 95% CI 1.233–2.786), age 10 to 12 years (OR 1.808, 95% CI 1.056–3.093), age 13 to 18 years (OR 2.136, 95% CI 1.080–4.225), parental history of scoliosis (OR 1.536, 95% CI 1.125–2.097), malnutrition (OR 1.413, 95% CI 1.045–1.911), heavy or very heavy schoolbag burden (OR 1.390, 95% CI 1.062–1.818), single-shoulder bag use (OR 1.806, 95% CI 1.142–2.857), sedentary time of at least 10 hours per day (OR 1.608, 95% CI 1.132–2.284), daily physical activity of less than 1 hour (OR 1.868, 95% CI 1.253–2.787), and unilateral-dominant exercise (OR 1.670, 95% CI 1.066–2.617) were associated with higher odds of scoliosis. Conclusions Scoliosis was relatively common in this urban adolescent population in Shanghai. The findings support regular school-community screening, family history assessment, improved schoolbag ergonomics, nutrition support, and strategies to reduce prolonged sedentary time while promoting adequate physical activity. These measures may strengthen local prevention and control of scoliosis in children and adolescents.