Effects of Hospital-Acquired Conditions on Readmission Risk: The Mediating Role of Length of Stay.

This article examines the relationship between hospital-acquired conditions (HACs)—undesirable complications occurring during hospital stays—and their impact on length of stay (LOS) performance and 30-day readmission risk among patients hospitalized for acute myocardial infarction (AMI), heart failure (HF), and pneumonia (PN) in Florida from 2010 to 2014. Using patient-level data and econometric analyses, the study finds that exposure to HACs increases the odds of readmission by 37% and lengthens LOS by 79% relative to the Centers for Medicare and Medicaid Services' (CMS) Geometric Mean LOS (GMLOS) standard. Importantly, the deviation of LOS from GMLOS mediates the HAC-readmission relationship, with longer LOS substantially reducing readmission risk for HAC patients—benefits that plateau when LOS exceeds about 65% above GMLOS. The findings suggest that LOS is a critical, hospital-controlled mechanism to mitigate the adverse effects of HACs on readmissions, offering practical guidance for clinicians on discharge timing and informing policy discussions on refining CMS reimbursement and quality measures.