Nurse staffing and patient outcomes: Strengths and limitations of the evidence to inform policy and practice. A review and discussion paper based on evidence reviewed for the National Institute for Health and Care Excellence Safe Staffing guideline development

Abstract

What is already known? A number of high quality reviews establish an association between lower registered nurse staffing levels, increased mortality rates and other adverse outcomes  Careful analysis of this evidence suggests that it is consistent with a causal relationship  Translation of this evidence into practice is disputedWhat this paper adds  This paper summarises and extends a recent systematic review on nurse staffing and outcomes undertaken for England's National Institute for Health and Care Excellence  Methodological limitations mean that existing studies may not give unbiased estimates of the benefits from increased nurse staffing, with over and underestimation of benefit both possible, which makes it difficult to directly translate evidence into guidance for practice. We identify avenues for progressing this important research so that future studies might be better able to provide the evidence needed to inform policy and practice, and provide a checklist to aid future study development AbstractA large and increasing number of studies have reported a relationship between low nurse staffing levels and adverse outcomes, including higher mortality rates. Despite the evidence being extensive in size, and having been sometimes described as "compelling" and "overwhelming", there are limitations that existing studies have not yet been able to address. One result of these weaknesses can be observed in the guidelines on safe staffing in acute hospital wards issued by the influential body that sets standards for the National Health Service in England, the National Institute for Health and Care Excellence (NICE), which concluded there is insufficient good quality evidence available to fully inform practice.In this paper we explore this apparent contradiction. After summarising the evidence review that informed the NICE guideline on safe staffing and related evidence, we move on to discussing the complex challenges that arise when attempting to apply this evidence to practice. Among these, we introduce the concept of endogeneity, a form of bias in the estimation of causal effects. Although current evidence is broadly consistent with a cause and effect relationship, endogeneity means that estimates of the size of effect, essential for building an economic case, may be biased and in some cases qualitatively wrong. We expand on three limitations that are likely to lead to endogeneity in many previous studies: omitted variables, which refers to the absence of control for variables such as medical staffing and patient case mix; simultaneity, which occurs when the outcome can influence the level of staffing just as staffing influences outcome; and common-method variance, which may be present when both outcomes and staffing levels variables are derived from the same survey.Thus while current evidence is important and has influenced policy because it illustrates the potential risks and benefits associated with changes in nurse staffing, it may not provide operational solutions. We conclude by posing a ser...

The Impact of Heavy Perceived Nurse Workloads on Patient and Nurse Outcomes

“…. " [14] (p. 24). Some moderating/mediating mechanisms that have been explored to date include missed care [5] and care left undone [15].…”

What impact does nursing care left undone have on patient outcomes? Review of the literature

“…A considerable body of evidence supports the hypothesis that lower levels of registered nurses on duty increase the likelihood of patients dying on hospital wards (Griffiths et al., 2016; Needleman et al., 2011) and the risk of many aspects of care being either delayed or left undone (Ausserhofer et al., 2014). Guidelines on safe staffing published by the National Institute for Care and Health Excellence (NICE) highlighted the need for more evidence and indicators to determine safe nurse staffing levels, and studies to determine the extent to which they are achieved in practice.…”

Correlação entre o tempo de assistência de enfermagem e indicadores de qualidade assistencial em Unidades de Terapia Intensiva

“…Estudo de revisão sistemática, desenvolvido por pesquisadores do Reino Unido (Griffiths et al, 2016), com base no relatório do National Institute for Health and Care Excellence Safe Staffing, elaborado no mesmo país, intitulado, "Quadro de pessoal de enfermagem e os resultados da assistência aos pacientes: pontos fortes e limitações da evidência para formação de políticas e práticas de trabalho", retrata que a base de evidências para associações entre quadro de recursos humanos de enfermagem e os resultados/qualidade da assistência é composta exclusivamente por estudos observacionais.…”

“…As variáveis não coletadas podem envolver a natureza jurídica do hospital (público, privado, ensino), o modelo de gestão de recursos humanos, competência dos profissionais da equipe de saúde e ambiente da prática (Griffiths et al, 2016).…”

“…No que tange à simultaneidade, embora os estudos que examinam a associação entre o quadro de pessoal de enfermagem e os resultados da assistência assumam uma causalidade direta (relação entre o quantitativo de pessoal de enfermagem e os resultados da assistência), outras variáveis podem influenciar nos resultados da assistência, como, idade, diagnóstico, carga de trabalho requerida pelos pacientes, protocolos institucionais, dentre outros (Griffiths et al, 2016).…”