Clinical Prediction Rules That Don't Hold Up-Where to Go From Here?

Clinical prediction rules (CPRs) are created to help guide clinical decision making. To do this, they use the presence or absence of certain factors that have been shown to meaningfully predict a patient's prognosis, diagnosis, or response to treatment. While representing a seminal methodological step forward in individualized care, one of the main drawbacks of CPRs continues to be validation studies that do not support the initially derived CPR. This is particularly important because validation of CPRs in an independent patient population prior to clinical implementation is essential. Why is it quite common for existing CPRs to fall down at the validation stage? And what does this mean for research that aims to individualize treatment? J Orthop Sports Phys Ther 2016;46(7):502-505. doi:10.2519/jospt.2016.0606.