Prevalence, risk of progression and quality of life in adolescents undergoing school screening for AIS in the metropolitan region of Chile

Introduction: The prevalence (PR) of Adolescent idiopathic scoliosis (AIS) varies around the world, with the far- thest countries from the Equator reporting a greater PR of AIS compared to countries closer to it. Epidemiological evidence from South America is very scarce due to the lack of PR studies conducted. Consequently, statistical information relating to the PR of AIS in Chile is not currently available in the Chilean National Scoliosis Guide- lines (CNSG). Objectives: To determine the prevalence (PR), risk of progression (ROP) and quality of life (QOL) of the AIS pop- ulation in children aged 10 to 18 years old (yo) screened in schools within the Metropolitan Region of Chile. Methods: Research design. A cross-sectional convenience study. Participants. 1200 students aged between 10-18 yo. Instrumentation. A manual scoliometer, full spine Antero-Posterior (AP) and lateral x-ray. Procedure. Children were asked to perform the Adam’s Test in both standing and sitting. The ATR was measured with a scoliometer at: the thoracic (T3 to T11), thoracolumbar (T12 to L1), and lumbar area (L1 to L4). When ATR was ≥ 6°, a referral order for an AP and lateral x-ray was undertaken. An orthopedic surgeon undertook all the mea- surements. Data analysis. A Scoliosis diagnosis was confirmed when the Cobb angle ≥ to 10° together with the presence of vertebral rotation. The ROP was calculated and the QoL data analysis for CAVIDRA and TAPS results were analyzed using Spearman Correlation Coefficient. Final results: 1200 students were screened for scoliosis. The following was found: 54,92% (659) female and 49,08% (541) male students. 8,08% (97 students) had an ATR (> or = 6°) and were referred for an x-ray. 40 students had a scoliosis diagnosis confirmed (43.2%); 31 students did not have scoliosis (31.9%); 24 children were excluded due to no x-ray (24.7%) and three students had previously been diagnosed with scoliosis (3.09%). Mild scoliosis was found in 3.08% (37 subjects in total (22 females and 15 males); moderate scoliosis in 0.33% (of which were 4 females); two females had severe scoliosis (0.16%). The final PR rate was 3.58%. The most common scoliosis patterns and the distribution of cases with different ROP can be seen in figure 1a and 1b re- spectively. 69% of the students diagnosed with scoliosis (30 of 43 students) answered the CAVIDRA and TAPS questionnaires. Their results correlated negatively with the curve severity. Spearman Correlation Coefficient showed a positive association that was however non-statistically significant (p =0.31). Discussion and Conclusions: The PR value (3.58%) is higher than values reported in much of the literature. Grivas et al suggested that higher PR values are found in countries far from the equator and this is applicable to Chile. Our results confirm the importance of the use of the scoliometer as an effective tool to early diagnose in younger children. The `late` scoliosis cases suggest that only using subjective evaluation, can lead to diagnos- tic mistakes, as they were not previously detected. It is recommended that the CNSG: 1. use the scoliometer to screen for AIS and 2. follow the SOSORT Guidelines recommendations to perform scoliosis screening twice in girls at 10 and 12 yo, and once in boys at age 13 or 14 (pubertal spurt). These final results provide an insight into the magnitude of the AIS health problem in Chile and suggest that CNSG, needs to be updated regarding to the prevention and public awareness.