- Follow a multivariate analysis (here logistic since the dependent variable will be "breaking ACL O / N"). To carry out this logistic regression, all factors for which p <0.25 will be included in the model. A descending step-by-step method will arrive at the final model which will contain only those factors whose p will be less than 5% and whose 95% CI of the OR will not contain 1. Possibly it will be possible to adjust The model on certain parameters and to look for possible interactions. The ORs and IC95% obtained will allow the gravity scores to be established.