Hospital diagnostic aggregation and risk-adjusted quality.

OBJECTIVE: To demonstrate the importance of diagnostic aggregation when assessing hospitals. DATA SOURCES: Patient data from the Victorian Admitted Episodes Database (VAED), 1999/2000 to 2004/2005. Financial statements from public hospitals, 2002/2003 to 2004/2005. STUDY
DESIGN: Risk-adjusted quality computed for each hospital using two aggregation levels. Each is then used to estimate the relationship between hospital efficiency and quality using two-stage DEA/Tobit model by Wilson and Simar (2006). DATA COLLECTION: Selected variables from the VAED were obtained from the Department of Health in Victoria, then linked anonymously with financial statements. PRINCIPAL
FINDINGS: Hospital quality and, in some cases, its relationship with efficiency differs depending on aggregations.
CONCLUSIONS: Patient risk adjustment should be conducted using more than one aggregation level whenever possible. © Health Research and Educational Trust.