Nurses matter: more evidence

Empirical evidence from many published studies indicates that better hospital professional registered nurse (RN) staffing is associated with better patient outcomes, including lower mortality and failure to rescue, shorter lengths of stay, fewer readmissions, fewer complications, higher patient satisfaction and more favourable reports from patients and nurses alike related to quality of care and patient safety.1–10 There are nonetheless lingering questions and concerns about these studies and the evidence they provide. In this issue of BMJ Quality & Safety , Needleman et al 11 allude to some potentially important ones in their introduction to their paper, including making causal inferences from cross-sectional studies, the absence of evidence on whether there is an optimal level of staffing or some level of minimally acceptable staffing below which nurses are unable to deliver high-quality and safe care, the absence of measures of work environment and its impact in many studies and whether the greater or lesser presence of nursing support staff affects patient outcomes independent of, or that acts in conjunction with, the level of RN staffing. With this study by Needleman and colleagues, BMJ Quality & Safety has now published three recent papers on the outcomes of hospital nurse staffing11–13 that are responsive in different ways to some of the lingering questions about the outcomes of nurse staffing and their implications for policies and managerial decisions about investments in nursing personnel to achieve the greatest value. The first paper in the series by RN4CAST researchers12 used unique cross-sectional data to study the outcomes of variation in nurse staffing in 243 hospitals in six European countries. The outcomes included were mortality among patients who had undergone common surgical procedures, patients’ ratings of their hospitals, nurses’ assessments of quality of care and adverse care outcomes, and nurse burnout and job dissatisfaction. …