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. 2017 Dec;7(1):46.
doi: 10.1186/s13613-017-0269-2. Epub 2017 May 2.

Are high nurse workload/staffing ratios associated with decreased survival in critically ill patients? A cohort study

Anna Lee  1 , Yip Sing Leo Cheung  2 , Gavin Matthew Joynt  1 , Czarina Chi Hung Leung  1 , Wai-Tat Wong  1 , Charles David Gomersall  3
Affiliations

Are high nurse workload/staffing ratios associated with decreased survival in critically ill patients? A cohort study

Anna Lee et al. Ann Intensive Care. 2017 Dec.

Abstract

Background: Despite the central role of nurses in intensive care, a relationship between intensive care nurse workload/staffing ratios and survival has not been clearly established. We determined whether there is a threshold workload/staffing ratio above which the probability of hospital survival is reduced and then modeled the relationship between exposure to inadequate staffing at any stage of a patient's ICU stay and risk-adjusted hospital survival.

Methods: Retrospective analysis of prospectively collected data from a cohort of adult patients admitted to two multi-disciplinary Intensive Care Units was performed. The nursing workload [measured using the Therapeutic Intervention Scoring System (TISS-76)] for all patients in the ICU during each day to average number of bedside nurses per shift on that day (workload/nurse) ratio, severity of illness (using Acute Physiology and Chronic Health Evaluation III) and hospital survival were analysed using net-benefit regression methodology and logistic regression.

Results: A total of 894 separate admissions, representing 845 patients, were analysed. Our analysis shows that there was a 95% probability that survival to hospital discharge was more likely to occur when the maximum workload-to-nurse ratio was <40 and a more than 95% chance that death was more likely to occur when the ratio was >52. Patients exposed to a high workload/nurse ratio (≥52) for ≥1 day during their ICU stay had lower risk-adjusted odds of survival to hospital discharge compared to patients never exposed to a high ratio (odds ratio 0.35, 95% CI 0.16-0.79).

Conclusions: Exposing critically ill patients to high workload/staffing ratios is associated with a substantial reduction in the odds of survival.

Keywords: Critical care; Nurses; Personnel staffing; Workload.

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Figures

Fig. 1
Fig. 1
Maximum workload/nurse ratio with 90% confidence intervals from the net-benefit regression analysis
Fig. 2
Fig. 2
Calibration belt for logistic regression model examining the effect of workload/staffing ratio threshold set at 40 on survival
See this image and copyright information in PMC

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