Objective:The purpose of this study was to describe relationships among adverse patient occurrences aggregated at the unit level of measurement. Relationships between adverse occurrences and a patient acuity measure were also described.Background:Adverse patient occurrence data have been traditionally a major indicator of quality care in hospitals; however, few studies have examined relationships among these indicators or the usefulness of these indicators for assessing the quality of nursing care.Methods:A correlational design was used to examine and describe patterns of relationships among inpatient units in a tertiary care hospital. The results demonstrated positive correlations between medication error rates and patient falls; these adverse occurrences correlated negatively with pressure ulcers, infections, patient complaints, and death. Pressure ulcers, infections, patient complaints and death intercorrelated positively and also related positively to patient acuity levels.Results:An examination of these same rates for a subset of units with similar patient acuity levels revealed that most of the interrelationships among the entire set of adverse occurrence indicators were positive. When patient acuity was taken into account, these adverse outcomes appeared to indicate some common underlying characteristic of the units, such as quality of nursing care.Conclusions:This study suggests a relationship between the adverse occurrences that were correlated (pressure ulcers, patient complaints, infection, and death) and the severity of patient illness. Medication error rates and patient fall rates were not correlated with patient acuity and are more likely to indicate quality of nursing care across all types of units.