Temporary Staffing and Patient Death in Acute Care Hospitals: A Retrospective Longitudinal Study.

Purpose To explore the association between the levels of temporary nurse staffing and patient mortality. Achieving adequate nurse staffing levels plays a vital role in keeping patients safe from harm. The evidence around deploying temporary staffing to maintain safe staffing levels is mixed, with some studies reporting no adverse effects on patient mortality. Design A retrospective longitudinal observational study using routinely collected data on 138,133 patients admitted to a large hospital in the south of England. Data were collected between April 2012 and April 2015. Methods We used multilevel survival models to explore the association between in-hospital deaths and daily variation in registered nurse (RN) and nursing assistant (NA) temporary staffing, measured as hours per patient per day. Analyses controlled for unit and patient risk. Findings Use of temporary staffing was common, with only 24% (n = 7,529) of the 30,980 unit-days having no temporary RN staff and 13% (n = 3,951) having no temporary NAs. The hazard of death was increased by 12% for every day a patient experienced high levels (1.5 hr or more per day) of RN temporary staffing (adjusted hazard ratio [aHR] 1.12, 95% confidence interval [CI] 1.03-1.21). The hazard of death was increased on days when NA temporary staffing was more than 0.5 hr per patient (aHR 1.06; 95% CI 1.03-1.08). Conclusions Days with more than 1.5 hr per patient of temporary RNs and days with more than 0.5 hr of temporary NAs were associated with increased hazard of death. Clinical Relevance Heavy reliance on temporary staff is associated with higher risk for patients dying. There is no evidence of harm associated with modest use of temporary RNs so that required staffing levels can be maintained.