title: The relationship between nurse staffing and patient outcomes: a case study.
abstract: BACKGROUND
  Research has shown a direct relationship between staffing levels and patient outcomes for specific nurse-sensitive indicators, with lower patient to nurse ratios (i.e. less patients per nurse) associated with better outcomes.
  
  
  OBJECTIVE
  To explore the relationship between nurse staffing characteristics (the nursing hours worked by permanent and temporary staff and nurse hours per patient day) and patient outcomes: pressure sores, patient falls, upper gastrointestinal bleed, pneumonia, sepsis, shock and deep vein thrombosis.
  
  
  METHODS
  A case study using retrospective hospital data, at ward level.
  
  
  METHODS
  A tertiary cardio-respiratory NHS Trust in England, comprising two hospitals.
  
  
  METHODS
  All patients, including day cases, who were admitted to either hospital as an in-patient over 12 months.
  
  
  METHODS
  Data were extracted from corporate hospital systems. The clinical areas were categorised as lower dependency, i.e. wards, or critical care which included ICU and high dependency units. The relationship between nurse staffing characteristics and patient outcomes was assessed using either a Poisson or negative binomial regression model as appropriate. We sought to establish whether the outcomes were affected by the nurse hours per patient day, the permanent nurse hours worked as a percentage of the total hours, and the permanent nurse hours worked as a percentage of the permanent and bank hours combined.
  
  
  RESULTS
  In the lower dependency category wards there was only a weak association demonstrated between nurse staffing and the majority of the outcomes. The results from the high dependency critical care areas showed few significant results with only the rate of sepsis being significantly reduced as the ratio of permanent staff hours increased.
  
  
  CONCLUSIONS
  The study demonstrated the possibility of using existing hospital data to examine the relationship between nurse staffing and patient outcomes, however the associations found were weak and did not replicate reliably the findings from previous work.
authors.affiliation: Royal Brompton & Harefield NHS Trust, Sydney Street, London SW3 6NP, UK. c.shuldham@rbht.nhs.uk
authors.forename: Caroline
authors.initials: C
authors.lastname: Shuldham
authors.forename: Claire
authors.initials: C
authors.lastname: Parkin
authors.forename: Ashi
authors.initials: A
authors.lastname: Firouzi
authors.forename: Michael
authors.initials: M
authors.lastname: Roughton
authors.forename: Margaret
authors.initials: M
authors.lastname: Lau-Walker
mesh_terms: D004739:England; D009741:Nursing Staff, Hospital; D017063:Outcome Assessment, Health Care; D010561:Personnel Staffing and Scheduling; D012189:Retrospective Studies; D013222:State Medicine