- The Ottawa clinical decision rules provide guidelines for doctors to determine if x-rays are needed for patients presenting with ankle, foot, or knee injuries. - Previously, most patients would receive x-rays but only 15% revealed fractures, resulting in many unnecessary x-rays. - This study prospectively validated the rules in over 2500 patients in India. It found the rules to be highly sensitive for detecting fractures while allowing for a 32% reduction in unnecessary x-rays. - Applying the rules correctly identified fractures in 95.6% of ankle, 98% of foot, and 100% of knee cases while avoiding many x-rays not needed. This decreased wait times and costs while avoiding potential health risks