Since that report, and in part in response to it, the number of studies examining the association of staffing and quality in hospitals has exploded. Major studies demonstrating the association of nurse staffing and patient outcomes, including lengths-of-stay, mortality, pressure ulcers, deep vein thromboses, and hospital-acquired pneumonia have been published in first-tier journals, and several major literature reviews, syntheses, and meta-analyses have been published confirming the association of nurse staffing with patient outcomes.5 When the IOM revisited the issue of nurse staffing and patient care in 2004, it concluded: “Research is now beginning to document what physicians, patients, other health care providers, and nurses themselves have long known: how well we are cared for by nurses affects our health, and sometimes can be a matter of life or death.”