School screening for adolescent idiopathic scoliosis in China: a five-year evaluating the evaluation in Zhongshan city.

Early detection of Adolescent Idiopathic Scoliosis (AIS) is crucial to prevent progression to severe cases. School-based scoliosis screening programs can be effective in identifying students with suspected scoliosis and facilitating timely intervention. This study aimed to evaluate the effectiveness and accuracy of a school-based scoliosis screening (SSS) program in Zhongshan, China, and assess trends in case severity, with recommendations for improving future screening protocols. A longitudinal cohort study was conducted annually from 2017 to 2021, involving middle school students from three grade levels across multiple schools in Zhongshan, Guangdong Province, China. The SSS process included visual inspections, clinical assessments, and confirmatory X-rays for suspected cases. Key metrics such as Positive Test Rate (PTR), Further Testing Rate (FTR), Diagnosis Rate (DR), and severity proportions were analyzed. Sensitivity, number needed to screen (NNS), and positive predictive value (PPV) were also assessed. Over the five-year study period, 7,764 students screened positive for suspected scoliosis, of whom 51.6% (n = 4,376) underwent further diagnostic evaluation. Of those evaluated, 85.5% were radiographically confirmed as AIS. The estimated prevalence of AIS over the five years was 1.08%. The PPV was high, and the severity of confirmed cases decreased over the study period. Girls had higher positivity and PPV than boys and a greater proportion of severe cases. Positive screening rates increased across grade. The SSS program in Zhongshan identified students at risk and achieved a high diagnostic yield among those undergoing radiographic evaluation. Temporal changes in the severity distribution of confirmed AIS cases were observed over the study period. Sex- and grade-related patterns may help refine future screening strategies and support more targeted approaches to early detection and intervention.