Table 1

Variables included in the study

VariablesTypeNumeratorDenominatorUnitsTransformation applied?Interpretation
Breached attendancesOutcomeNumber of ED attendances greater than 4 hoursNumber of ED attendancesProportion of ED attendances waiting >4 hours
Cancelled electivesOutcomeNumber of cancelled elective operationsNumber of elective admissionsOperations per admissionLogRatio of cancelled elective operations to elective admissions. In absence of the number of planned elective operations, this is the most suitable denominator
Empty day bedsExplanatoryNumber of unoccupied day bedsNumber of day bedsCategorised (5)Ratio of unoccupied day beds to total number of day beds
Empty night bedsExplanatoryNumber of unoccupied night bedsNumber of night bedsLogRatio of unoccupied night beds to total number of night beds
Delayed transfersExplanatoryNumber of bed days taken by delayed transfersNumber of night beds10 bed-daysThe number of bed-days lost to delayed transfers for each night bed at a trust, over the course of a year
Day bed:night bed ratioExplanatoryNumber of day bedsNumber of night bedsRatio of total day beds to total night beds
ED conversion ratioExplanatoryNumber of emergency admissions via EDNumber of attendances at EDRatio of ED admissions to attendances. Often commonly referred to as ‘conversion ratio’
Admission casemix ratioExplanatoryNumber of non-elective (emergency) admissionsNumber of elective admissionsLogProportion of admissions that are emergency or ratio of emergency to elective admissions
Emergency admission/bed ratioExplanatoryNumber of non-elective (emergency) admissionsNumber of day and night beds10 admissionsNumber of emergency admissions per bed over the course of a year
  • ED, emergency department.