Trends in Incidence of Adolescent Idiopathic Scoliosis: A Modern US Population-based Study.

BACKGROUND: A successful disease screening strategy requires a high incidence of the condition, efficacy of early treatment, and efficient detection. There is limited population-based data describing trends in incidence of adolescent idiopathic scoliosis (AIS) in the United States and potential role of school screening programs on the incidence of AIS. Thus, we sought to evaluate the incidence of AIS over a 20-year period between 1994 and 2013 using a population-based cohort. METHODS: The study population comprised 1782 adolescents (aged 10 to 18 y) with AIS first diagnosed between January 1, 1994 and December 31, 2013. The complete medical records and radiographs were reviewed to confirm diagnosis and coronal Cobb angles at first diagnosis. Age-specific and sex-specific incidence rates were calculated and adjusted to the 2010 United States population. Poisson regression analyses were performed to examine incidence trends by age, sex, and calendar period. RESULTS: The overall age-adjusted and sex-adjusted annual incidence of AIS was 522.5 [95% confidence interval (CI): 498.2, 546.8] per 100,000 person-years. Incidence was about 2-fold higher in females than in males (732.3 vs. 338.8/100,000, P<0.05). The incidence of newly diagnosed AIS cases with radiographs showing a Cobb angle >10 degrees was 181.7 (95% CI: 167.5, 196.0) per 100,000 person-years. The overall incidence of AIS decreased significantly after discontinuation of school screening in 2004 (P<0.001). The incidence of bracing and surgery at initial diagnosis was 16.6 (95% CI: 12.3, 20.9) and 2.0 (95% CI: 0.5, 3.4) per 100,000 person-years, respectively. CONCLUSIONS: Overall population-based incidence of AIS decreased after school screening was discontinued. However, incidence of patients with a Cobb angle >10 degrees, initiation of bracing and surgery did not change significantly over time. This provides further data to help determine the role of scoliosis screening. LEVEL OF EVIDENCE: Level III.

Does School Screening Affect Scoliosis Curve Magnitude at Presentation to a Pediatric Orthopedic Clinic?

BACKGROUND: With new data supporting the efficacy of bracing, the role of school screening for early detection of moderate scoliosis curves has been revisited. Because of a high rate of false-positive screening and cost concerns, a comprehensive county-wide school screening program was discontinued in 2004. We aim to determine the impact of a comprehensive school screening program on curve magnitude at presentation and initial scoliosis treatment for all local county patients presenting to a pediatric orthopedic clinic from all referral sources. METHODS: Between 1994 and 2014, a total of 761 county patients presented to a pediatric orthopedic clinic for new scoliosis evaluation. Curve magnitude and recommended treatment were recorded. Treatment indications for bracing, surgery, and observation were consistent over the study period. RESULTS: From January 1994 to July 2004 (school screening period), 514 children were seen by a pediatric orthopedic specialist for scoliosis evaluation compared to 247 patients from August 2004 to December 2014 (no school screening). There was a 48% decrease in the number of county children who were evaluated for idiopathic scoliosis by pediatric orthopedics once school screening was discontinued. Mean maximal Cobb angle at presentation increased from 20° (range, 4°-65°) to 23° (range, 7°-57°). At presentation, 5 of 514 (0.97%) patients in the screened group required surgery and 68 of 514 (13.2%) required bracing, compared to 3 of 247 (1.2%) patients in the nonscreened group requiring surgery and 47 of 247 (19%) requiring bracing (p>.05, p=.04, respectively). CONCLUSION: After school screening was discontinued, mean curve magnitude and rates of bracing at presentation statistically increased in county patients evaluated for new scoliosis, although the clinical significance is unclear. After school screening was discontinued, there were fewer patient referrals, braces prescribed, and unnecessary evaluations (patients discharged at first visit). This study provides data to evaluate the role of school screening for children with regular access to health care. LEVEL OF EVIDENCE: Level 3.