Variation in length of stay within and between hospitals

Abstract

Background and objective: Variation in the delivery of health care services and the lack of association between greater utilization and higher quality care signal inefficient, low value care. The extent to which patient and hospital variables can explain variation in hospital length of stay is unclear. Methods: We examined hospital inpatient length of stay using data from 684 hospitals and 5.4 million discharges in the 2007 Healthcare Cost and Utilization Project’s Nationwide Inpatient Sample. We used a mixed effects model with a random effect for hospitals to quantify variation in length of stay due to differences within and between hospitals. Results: The interquartile range of hospital mean LOS was 3.4 days (3.3-6.7). Fifty-nine percent of the overall variation in length of stay remained unexplained after adjustment for discharge-level disease status, illness-severity, regional poverty, hospital-level contextual factors (e.g. proportion of patients from low-income ZIP-codes, proportion uninsured), and structural variables (e.g. teaching status, urban or rural location). Seventy-seven percent of the explainable variation was due to differences between hospitals. Conclusion: These findings indicate that wide variability in length of stay persists after adjustment for patient and hospital variables, signaling an opportunity for improved productivity and efficiency in the delivery of health care.