The Demographics and Epidemiology of Infantile, Juvenile, and Adolescent Idiopathic Scoliosis in a Southern California Integrated Health Care System

Study Design. Prognostic study, Level III. Objectives. The aim of this study was to determine the incidence and demographics of idiopathic scoliosis (IS) in a large cohort of children in a Southern California integrated healthcare system, and to identify the demographic or clinical factors associated with the greatest risk of IS. Summary of Background Data. Although many authors have reported on the incidence and prevalence of IS in children, there have been few incidence studies in the United States on large, self-contained populations. Methods. A retrospective chart analysis was done on diagnosed cases of IS within our integrated health care system in patients under age 18 years during the entire 2013 calendar year. Patient demographics were recorded and the incidence of IS was determined. Odds ratios (ORs) for having IS and for having more severe initial curve magnitudes based on demographics were determined using logistic regression models. Results. IS Incidence was 3.9, 28.6, and 393 per 100,000, respectively, for the infantile, juvenile, and adolescent group. The female incidence was more than twice that of males in all age groups. Multivariate logistic regression analysis showed Asians and non-Hispanic Whites had the highest OR of IS (OR 1.54 and 1.32 with 95% confidence interval [CI] 1.33-1.79 and 1.19-1.47). Whites, Blacks, and mixed-race patients had a significantly higher initial curve magnitude than Hispanics; females also had a significantly greater initial curve magnitude than boys (18.1 degrees vs. 16.7 degrees). Underweight patients had a 50% increased OR of IS versus normal weight (95% CI 1.16-1.94) with a progressively decreased OR of IS as weight increased. Conclusion. Our study of a large integrated healthcare system sheds light on the incidence of IS and the ORs based on weight, sex, and ethnicity/race. The overall incidence was lower overall than previously thought.