The relationship between hospital systems load and patient harm.

The objective of this study was to describe the relationship between patient harm due to health-care errors and the stresses on the hospital systems that occur because of the patients in need of care. Two California hospitals each provided 1 year of data to study the relationship between patient harm and Hospital Systems Load. This observational study used 2 metrics, Hospital Systems Load and patient harm. Hospital Systems Load was a composite measure consisting of the areas in the hospital most sensitive to intensity of service developed using factor analysis and clinical judgment to select the components. Patient harm was assessed using a weighted measure of all hospital incidents occurring during a single day and another controlling for census. Analyses were performed separately for each hospital, and each was broken up into weekdays and weekends. These 8 conditions were compared using a Pearson's r and a trend analysis. Patient harm trended upward as the Hospital Systems Load increased. Six of the 8 analyses were statistically significant. The results of this analysis are highly suggestive of a relationship between Hospital Systems Load and patient harm.