Introduction: School screening for adolescent idiopathic scoliosis (AIS) has been criticized as resulting in over-referrals for radiography and having low predictive values.
Objectives: To evaluate the clinical effectiveness of school scoliosis screening using a large and long-term-followed cohort of students in Hong Kong.
Materials and Methods: Retrospective cohort study. A total of 157,444 students were eligible for a biennial scoliosis screening, and their screening results and medical records up to 19 years of age were available. Screening tests included a forward bending test (FBT), angle of trunk rotation (ATR), and moiré topography for those who showed signs of AIS. Students with an ATR ≥15°, ≥2 moire lines, or significant clinical signs were referred for radiography and had their Cobb angle measured.
Results: Of the 115,190 screened students in the cohort, 3,228 (2.8%, 95% CI = 2.7% to 2.9%) were referred for radiography. At the final follow-up, the positive predictive values were 43.6% (41.8% to 45.3%) for a Cobb angle ≥20° and 9.4% (8.4% to 10.5%) for needing treatment, while the sensitivities were 88.1% (86.4% to 89.6%) and 80.0% (75.6% to 83.9%), respectively.
Conclusion: This study demonstrated that school scoliosis screening in Hong Kong is predictive and sensitive with a low referral rate. Screening should thus be continued in order to facilitate early administration of conservative treatments.
Significance: This was the largest study that responds to the need of large, retrospective cohort studies with sufficient follow-up to properly assess the clinical effectiveness of school scoliosis screening.