Length of stay: an appropriate quality measure?

HYPOTHESIS: Although demographic and clinical information are known to affect hospital length of stay (LOS), we hypothesized that LOS after traumatic injury would be significantly influenced by nonclinical factors.
DESIGN: Retrospective database analysis. PATIENTS: Trauma patients treated at hospitals participating in data submission to the National Trauma Data Bank.
METHODS: The National Trauma Data Bank was queried for all patients older than 18 years with an LOS longer than 48 hours and complete demographic information including age, sex, and race/ethnicity; nonclinical factors including payment type (commercial, Medicaid, Medicare, uninsured, and other) and discharge destination (home, rehabilitation facility, nursing home, and other); and clinical information (body region injured, Injury Severity Score, and Revised Trauma Score). Statistical analysis was performed using generalized linear modeling adjusted for multiple comparisons. MAIN OUTCOME MEASURES: Length of stay greater than the mean.
RESULTS: We obtained 313 144 medical records. Mean LOS was 9.6 days. Discharge destination had the greatest effect on LOS. Mean LOS for patients with Medicaid (11.3 days) was significantly longer than for patients with commercial insurance and uninsured patients (each 9.3 days) and patients with Medicare (8.8 days). Length of stay was longer for patients discharged to a nursing home (14.2 days) or rehabilitation facility (11.5 days) compared with those discharged to any other facility (9.6 days). In multivariate analysis, factors significantly associated with extended LOS included age, sex, race/ethnicity, insurance status, discharge destination, and Revised Trauma Score.
CONCLUSIONS: Nonclinical factors significantly influence LOS. If LOS is used as a quality measure for injured patients, adjustment for these factors is necessary.