Figure 4. Readmission by hospital volume.
Relationship between LOSa from initial hospitalization and readmission rate at (A) 7 days (p<0.0001) and (B) 30 days (p<0.0001) for the entire cohort, or for just those patients discharged from a surgical service (C, D). The associated fitted robust linear regression is shown as is the R2 correlation value for each relationship.