Nurse-to-Nurse Familiarity and Mortality in the Critically Ill. A Multicenter Observational Study

RATIONALE

Nurse-to-nurse familiarity at work should strengthen the components of team working and enhance its efficiency. However, its impact on patient outcomes in critical care remains poorly investigated.

OBJECTIVES

To explore the role of nurse-to-nurse familiarity on inpatient deaths during intensive care unit stay.

METHODS

Retrospective observational study in eight adult academic intensive care units between 01/01/2011 and 31/12/2016.

MEASUREMENTS AND MAIN RESULTS

Nurse-to-nurse familiarity was measured across day and night 12-hour daily shifts as the mean number of previous collaborations between each nursing team member during previous shifts within the given Intensive Care Unit (suboptimal if<50). Primary outcome was a shift with at least one inpatient death, excluding death of patients with a decision to forego life-sustaining therapy. A multiple modified Poisson regression was computed to identify the determinants of mortality per shift, taking into account intensive care unit, patients' characteristics, patient-to-nurse and patient-to-assistant nurse ratios, nurse experience length and workload. A total of 43,479 patients were admitted of whom 3,311 (8%) died. Adjusted model showed a lower risk of a shift with mortality when nurse-to-nurse familiarity increased in the shift (relative risk 0.90 [0.82-0.98] 95%confidence intervals per 10 shifts, p=0.012). Low nurse-to-nurse familiarity during the shift combined with suboptimal patient-to-nurse and assistant-nurse ratios (suboptimal if >2.5 and >4, respectively) were associated with increased risk of shift with mortality (1.84 [1.15-2.96], p<0.001).

CONCLUSIONS

Shifts with low nurse-to-nurse familiarity were associated with an increased risk of patient deaths.