PROVINCIAL EPIDEMIOLOGICAL TRENDS OF ADOLESCENT IDIOPATHIC SCOLIOSIS OVER 17 YEARS: VALIDATING A POPULATION-BASED ADMINISTRATIVE DATA ALGORITHM FOR PATIENT IDENTIFICATION

This study explores provincial epidemiological trends of adolescent idiopathic scoliosis (AIS) over 17-years, by validating a population-based health administrative data (HAD) algorithm for patient identification. This case ascertainment validation study developed 93 algorithms to identify 10 & 17-year-olds with AIS, using a combination of diagnostic, specialty, and/or fee codes related to scoliosis, gathered from physician billings, emergency room records, and discharge data over various look-back periods. A validation cohort was established to evaluate algorithm performance, comprised of 2732 patients with confirmed AIS (positive reference) and 49,049 youth without AIS (negative reference), approximating the population prevalence reported in the literature. Performance was evaluated based on measures of sensitivity, specificity, and positive and negative predictive value (PPV and NPV) with 95% confidence intervals. The top performing algorithm was used to derive a provincial cohort of youth diagnosed with AIS between 2005–21 to estimate annual incidence (2005–21) and prevalence (2012–21). The age/sex-adjusted estimates were directly standardized to the 2016 Census population and rates over time were compared using Chi-squared analyses, with p