National Emergency Access Targets metrics of the emergency department-inpatient interface: measures of patient flow and mortality for emergency admissions to hospital.

Background: Movement of emergency patients across the emergency department (ED)-inpatient ward interface influences compliance with National Emergency Access Targets (NEAT). Uncertainty exists as to how best measure patient flow, NEAT compliance and patient mortality across this interface.

Objective: To compare the association of NEAT with new and traditional markers of patient flow across the ED-inpatient interface and to investigate new markers of mortality and NEAT compliance across this interface.

Methods: Retrospective study of consecutive emergency admissions to a tertiary hospital (January 2012 to June 2014) using routinely collected hospital data. The practical access number for emergency (PANE) and inpatient cubicles in emergency (ICE) are new measures reflecting boarding of inpatients in ED; traditional markers were hospital bed occupancy and ED attendance numbers. The Hospital Standardised Mortality Ratio (HSMR) for patients admitted via ED (eHSMR) was correlated with inpatientNEAT compliance rates. Linear regression analyses assessed for statistically significant associations (expressed as Pearson R coefficient) between all measures and inpatient NEAT compliance rates.

Results: PANE and ICE were inversely related to inpatient NEAT compliance rates (r = 0.698 and 0.734 respectively, P < 0.003 for both); no significant relation was seen with traditional patient flow markers. Inpatient NEAT compliance rates were inversely related to both eHSMR (r = 0.914, P = 0.0006) and all-patient HSMR (r = 0.943, P = 0.0001).

Conclusions: Traditional markers of patient flow do not correlate with inpatient NEAT compliance in contrast to two new markers of inpatient boarding in ED (PANE and ICE). Standardised mortality rates for both emergency and all patients show a strong inverse relation with inpatient NEAT compliance.