Prevalence and determinants of adolescent idiopathic scoliosis from school screening in Xiaoshan District, Hangzhou, China

Abstract

Objective: This large-scale epidemiological study aimed to determine the prevalence and associated risk factors of Adolescent Idiopathic Scoliosis (AIS) through school-based screening in Xiaoshan District, Hangzhou, China.

Methods: A prospective cross-sectional study was conducted from 2023 to 2024, involving a total of 172,127 students aged between 7 and 18 years. A two-phase screening protocol was implemented: Phase I included physical examinations (assessing shoulder asymmetry and spinal curvature) alongside the Adams Forward Bend Test (with an angle of trunk rotation [ATR] ≥ 5°), while Phase II confirmed diagnoses through radiographic evaluation (Cobb angle ≥10°). Multivariate logistic regression analysis was employed to evaluate demographic, postural, and lifestyle factors.

Results: The overall prevalence of AIS was found to be 1.23%, with a significant gender disparity observed (female: 1.71% vs. male: 0.92%, p < 0.001). Among the initial cohort of 4,482 screen-positive cases, hospital confirmation was obtained for 422 individuals, identifying a total of 199 AIS patients (146 mild cases, 47 moderate cases, and one severe case). Key risk factors identified included female gender (odds ratio [OR] = 2.742), postural abnormalities such as kyphosis (OR = 5.741), enrollment in junior high school (OR = 0.414), prolonged sedentary behavior exceeding 8 h per day (OR = 0.231), and family history of scoliosis (OR = 0.467). Notably, the prone position test effectively reduced false-positive rates by approximately 70.3%. Twin studies indicated no significant concordance regarding AIS diagnosis among siblings (p = 0.16).

Conclusion: This study establishes that the prevalence of AIS in Xiaoshan District is consistent with national data reporting an incidence rate of approximately 1.2%. It highlights specific susceptibility based on gender as well as modifiable lifestyle risks associated with this condition. The integrated screening protocol that combines postural assessment with the Adams test demonstrates clinical utility for early detection efforts in schools. These findings underscore the necessity for preventive strategies within educational settings that focus on promoting proper posture education and encouraging increased physical activity among students.

Keywords: adolescents; epidemiology; idiopathic scoliosis; prevalence; screening.

Figure 1

Flow chart of initial screening at the AIS campus. Abnormal posture on general examination, and positive Adams test, girls with a family history of scoliosis were recommended to go to hospital for the next stage of examination.

Figure 2

Standardized dorsal and lateral view photographs were obtained during the routine physical examination of the subject.

Figure 3

Standardized photographic documentation of both the subject in the Adams forward bending test position and the examiner's manual palpation procedure was obtained during the spinal deformity assessment.

Figure 4

Histograms showing the frequency (A) and proportion (B) of the students participating in the school AIS screening in Xiaoshan District.

Figure 5

Histograms showing the frequency (A) and proportion (B) of the Adams-positive students participating in the school AIS screening in Xiaoshan District.

Figure 6

Box plot showing median (central dark line) quartiles 1 and 3, as well as minimum and maximum values as Adams-positive/negative groups for age.