Quantitative study—other Higher nurse staffing levels associated with reductions in unplanned readmissions to intensive care or operating theatre, and in postoperative in-hospital mortality in heart surgery patients Steven A Frost, 1,2 Evan Alexandrou 1,2 Commentary on: Diya L, Van den Heede K, Sermeus W, Lesaffre E. The relationship between in-hos- pital mortality, readmission into the intensive care nursing unit and/or operating theatre and nurse staffing levels. J Adv Nurs 2012;68:1073–81. Implications for practice and research ▪ Higher nurse staffing levels for postoperative care of cardiac surgery patients reduces the risk of unplanned re-admission to the intensive care or operating theatre and in-hospital mortality. ▪ Larger international studies are needed to assess the effect of nurse staffing levels and risk of hospital- wide adverse events. Context The effect of nurse staffing levels associated with adverse events in the hospital setting has been an important area of patient safety research. Market forces, in particular in North America, have resulted in efforts to reduce costs in all sectors of the healthcare setting. 1 Throughout the world, nurse staffing levels have been shown to be asso- ciated with adverse events in the hospital setting. 1–3 The rate of unplanned re-admission to the intensive care unit (ICU) has been widely used as an indicator of the quality of care of patients in the hospital setting. 4 In par- ticular, patients readmitted to the ICU have been observed to have significantly higher in-hospital mortality. 45 Other markers of the quality of care being regularly reported have included hospital mortality and unplanned return to the operating theatre (in surgical patients). In particular, 10.1136/eb-2012-100893 1 School of Nursing and Midwifery, University of Western Sydney, Penrith, New South Wales, Australia 2 Department of Intensive Care, Intensive Care, Liverpool Hospital, Liverpool, New South Wales, Australia Correspondence to: Steven A Frost University of Western Sydney, Campbelltown Campus, Bld 7 locked bag 1797, Penrith, NSW 2751, Australia; S.Frost@uws.edu.au 62 Evidence-Based Nursing April 2013 | volume 16 | number 2 | Nursing issues