highly significantp < 0.001
As far as length of stay is concerned, patients were divided into three groups, depending on whether the length of stay lasted 7 days or less (144 patients; group A), between 8 and 14 days (412 patients; group B) or more than 14 days (221 patients; group C); a highly significant difference in the probability of readmission was found ( p < 0.001; Fig. 2 b).