Over the last 2 decades, researchers from diverse disciplines have explored the relationship between hospital nursing characteristics, such as patient-to-nurse staffing ratios and work environments, and patient outcomes, including mortality, length of stay, and readmission. The overall body of evidence supports a positive association between more favorable nursing characteristics and better outcomes in pediatric and other patient populations,1 and yet hospitals and health systems grapple with nursing resource allocation, a significant line-item operating expense. What are missing from the literature, and what research end users desire, are robust evaluations of likely causal mechanisms underlying these associations. How does a lower patient-to-nurse ratio meaningfully influence patient care? How do better work environments for nurses translate into better clinical outcomes? And, on the basis of these answers, which interventions are most likely to work, be adopted, and be sustained over time? Missed nursing care, or required patient care that is omitted or delayed,2 is considered a plausible explanation for the observed associations between hospital nursing factors and patient outcomes. Exploration of missed nursing care as a process outcome of these hospital structural factors is a logical, if early, step in answering end users’ questions. In this issue of Hospital Pediatrics , Lake and colleagues3 describe the frequency and patterns of missed nursing care reported by registered nurses working in general pediatric units, NICUs, and PICUs. They also examine associations among nurse staffing ratios, work environments, and missed care. To do so, they present retrospective analyses of registered nurse survey data collected from 2006 to 2008 as part of a larger study on nurse workload and patient outcomes. A total of 2187 general pediatric, NICU, and PICU nurses reported on a variety of characteristics of their …