Our hypothesis that there would be no association between the Pressure Ulcer and Fall Rate Quality Composite Index and percent of nursing hours supplied by agency nurses was not supported; instead, the higher the percent of hours supplied by agency staff, the lower the Pressure Ulcer and Fall Rate Quality Composite Index. Two previous studies found no relationship between agency staff and hospital-acquired pressure ulcers and fall rate, however, both included smaller sample sizes than our study. One of these studies was based on a sample of 19 units in one hospital (Xue et al., 2012). In the other study the number of units was 1,610 (Dunton et al., 2007). Therefore, an explanation for our finding may be the larger sample size. More research is needed to explore the relationship.