title: Nurse staffing impact on quality of care in nursing homes: a systematic review of longitudinal studies.
abstract: BACKGROUND
  The relationship between nurse staffing and quality of care (QoC) in nursing homes continues to receive major attention. The evidence supporting this relationship, however, is weak because most studies employ a cross-sectional design. This review summarizes the findings from recent longitudinal studies.
  
  
  METHODS
  In April 2013, the databases PubMed, CINAHL, EMBASE, and PsycINFO were systematically searched. Studies were eligible if they (1) examined the relationship between nurse staffing and QoC outcomes, (2) included only nursing home data, (3) were original research articles describing quantitative, longitudinal studies, and (4) were written in English, Dutch, or German. The methodological quality of 20 studies was assessed using the Newcastle-Ottawa scale, excluding 2 low-quality articles for the analysis.
  
  
  RESULTS
  No consistent relationship was found between nurse staffing and QoC. Higher staffing levels were associated with better as well as lower QoC indicators. For example, for restraint use both positive (ie, less restraint use) and negative outcomes (ie, more restraint use) were found. With regard to pressure ulcers, we found that more staff led to fewer pressure ulcers and, therefore, better results, no matter who (registered nurse, licensed practical nurse/ licensed vocational nurse, or nurse assistant) delivered care.
  
  
  CONCLUSIONS
  No consistent evidence was found for a positive relationship between staffing and QoC. Although some positive indications were suggested, major methodological and theoretical weaknesses (eg, timing of data collection, assumed linear relationship between staffing and QoC) limit interpretation of results. Our findings demonstrate the necessity for well-designed longitudinal studies to gain a better insight into the relationship between nurse staffing and QoC in nursing homes.
authors: CAPHRI School for Public Health and Primary Care, Department of Health Services Research, Maastricht University, Maastricht, The Netherlands. Electronic address: r.backhaus@maastrichtuniversity.nl.
authors: Ramona
authors: R
authors: Backhaus
authors: CAPHRI School for Public Health and Primary Care, Department of Health Services Research, Maastricht University, Maastricht, The Netherlands.
authors: Hilde
authors: H
authors: Verbeek
authors: CAPHRI School for Public Health and Primary Care, Department of Health Services Research, Maastricht University, Maastricht, The Netherlands; Zuyd University of Applied Sciences, Research Centre on Autonomy and Participation, Heerlen, The Netherlands.
authors: Erik
authors: E
authors: van Rossum
authors: Hunter College, City University of New York, New York, NY.
authors: Elizabeth
authors: E
authors: Capezuti
authors: CAPHRI School for Public Health and Primary Care, Department of Health Services Research, Maastricht University, Maastricht, The Netherlands.
authors: Jan P H
authors: JP
authors: Hamers
mesh_terms: D000068:Accreditation; D000203:Activities of Daily Living; D006760:Hospitalization; D006801:Humans; D007239:Infections / Q000451:nursing; D008137:Longitudinal Studies; D009735:Nursing Homes; D009740:Nursing Staff / Q000600:supply & distribution*; D003668:Pressure Ulcer / Q000451:nursing; D011785:Quality Assurance, Health Care; D012149:Restraint, Physical; D014546:Urinary Catheterization / Q000451:nursing; D000078329:Workforce
keywords: Staffing; nursing homes; quality; review