Prospective Validation of the Calgary Kids' Hand Rule: A Clinical Prediction Rule for Pediatric Hand Fracture Triage

Introduction: Pediatric hand fractures are common and routinely referred to surgeons, yet most heal well without surgical intervention. This trend inspired the development of the Calgary Kids' Hand Rule (CKHR), a clinical prediction rule designed to predict "complex" fractures that require surgical referral. The CKHR was adapted into a checklist whereby the presence of any 1 of 6 clinically or radiologically identifiable fracture characteristics predicts a complex fracture. The aim of this study was to assess the accuracy of the CKHR in a prospective sample of children with hand fractures. Methods: Physicians were asked to complete the CKHR checklist when referring pediatric patients (< 18 years) to hand surgeons at a Canadian pediatric hospital (April 2019-September 2020). Completed checklists represented predicted outcomes and were compared to observed outcomes (determined via chart review). Predictive accuracy (primary outcome) was evaluated based on sensitivity and specificity. Secondary outcomes were interrater reliability between referring physicians and surgeons, and survey assessment of CKHR user satisfaction. Results: In total 365 fractures were included, with only 16 requiring surgical intervention. Overall performance of the CKHR was good with 84% sensitivity and 71% specificity. Percent agreement between referring physicians and surgeons ranged from 84.1% to 96.3% on individual predictors, with 78.1% agreement on the presence of any predictors. Survey results showed general user satisfaction but also identified areas for improvement. Conclusion: This study posits the CKHR as an accurate and clinically useful prediction rule and highlights the importance of education for its effective use and eventual scale and spread.