Clinical Prediction Rules for Diagnostic Imaging

true positive

test result is positive, person actually has disease/injury

true negative

test result is negative, person actually doesn't have disease/injury

sensitivity

ability of a test to correctly spot people who have the disease

specificity

ability of a test to correctly spot people who don't have the disease

positive likelihood ratio

how much a positive test result raises the odds of having a disease, >10

negative likelihood ratio

how much a negative test result lowers the odds of having a disease,

ottowa ankle rules

tenderness over tip of med/lat malleoli, pt unable to bear weigh for at least 4 steps immediately after injury or at time of evaluation

C-spine rules

patient is 65 or older, significant mechanism of injury, parasthesias in extremities, no delayed onset of neck pain, presence of midline c-spine tenderness, can't rotate neck actively 45 degrees to left and right

ottowa knee rules

older than 55, tenderness at fib head, isolated tenderness of patella, can't flex knee past 90 degrees, unable to weight bear 4 steps immediately after injury or at time of evaluation

pittsburgh knee rules

blunt fall/trauma, less than 12 or older than 50, tibia/fibula tenderness, unable to weight bear 4 steps immediately after injury or at time of evaluation