Study design: A cross-sectional study.
Objective: To estimate the prevalence of adolescent idiopathic scoliosis (AIS) in cities in the state of São Paulo, Brazil, as well as to identify demographic, clinical, and lifestyle factors associated with AIS.
Summary of background data: AIS is a common three-dimensional spinal deformity. Epidemiological data about the condition in the southern hemisphere are scarce, and Brazil has no public health policies to implement school-based scoliosis screening programs.
Methods: We assessed 2562 adolescents between 10 and 14 years of age. The screening procedure included measurement of the angle of trunk rotation using a scoliometer in the Adams forward bend test and the radiographic examination.
Results: The overall prevalence of AIS was 1.5% (95% confidence interval [CI]: 1%-1.9%). The AIS prevalence was higher among the females than among the males-2.2% (95% CI: 1.4%-2.9%) and 0.5% (95% CI: 0.1%-0.9%), respectively. The following factors were associated with the development of AIS: being female (OR = 4.7, 95% CI: 1.8-12.2; P = 0.001) and being in the 13- to 14-year age group (OR = 2.2; 95% CI: 1.0-4.8; P = 0.035). Double curves and right laterality were more common (59.4% and 56.8%, respectively), although the curves were of low magnitude (75% of the curves having a Cobb angle ≤22°), as was the progression factor (≤1.2 in 75% of the cases).
Conclusion: The prevalence of AIS in cities within the state of São Paulo was similar to that reported in the literature, was higher among females, and was higher during puberty (13-14 years of age). Because puberty occurs later for males than for females, the recommendation to screen both sexes at 10 to 14 years of age should be reconsidered.
Level of evidence: 3.