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Ruby Reetika Tripathi

Ruby Reetika Tripathi

University of Toronto, Canada

Title: Accuracy of the weight-for-age index in identifying obese children in the emergency setting

Biography

Ruby Reetika Tripathi is currently in final year of undergraduate studies at the University of Toronto where she is pursuing a major in Health and Disease as well as a minor in French and Italian. Her interest in this pediatric obesity research had been ignited by a two-year research project that she worked on in collaboration with several Pediatric Emergency Physicians at the Hospital for Sick Children & British Columbia Children's Hospital, entitled “Bone Fractures in Children - Is There an Association with Obesity?”

Abstract

Background: Obesity has been defined as weight-for-age >95th percentile for research/clinical settings like the emergency department where height is not routinely available. Objective: Our main objective was to determine the sensitivity of weight-for-age >95%th percentile in identifying obesity, using Body Mass Index (BMI)-for-age >95% percentile as the reference standard. We also determined the specificity, and predictive values, and the correlation between weight and BMI-for-age values. Methods: This was a cross-sectional study with prospectively collected data conducted at two urban, tertiary care pediatric emergency departments in Canada. Children between 2 and 17 years of age with acute extremity injuries were enrolled. Results: Of the 2259 participants, 1283 (56.1%) were male and the mean (SD) age was 9.5 (4.1) years. Using weight-for-age >95th percentile, 326 [14.3% (12.9, 15.7]) were classified as obese, while using BMI-for-age >95th percentile criteria determined that 363 [16.1% (14.6, 17.7)] were obese, p<0.0001. The sensitivity (95% CI) of weight-for-age >95th percentile to identify obesity was 62.2% (57.0, 67.2). The specificity, positive and negative predictive values were 94.5 % (93.6, 95.6), 14.4% (13.0, 16.0), and 85.6% (84.0, 87.0), respectively. The correlation between BMI and weight-for-age was 0.71 (0.68, 0.73). Conclusion: Although there may be limited validity in using this weight-for-age cut-off as a definition for obesity in research that includes children with acute injuries, the high specificity may provide some clinical utility in identifying two-thirds of children who are obese while minimizing false labeling of this condition.