Case mix, outcome and length of stay for admissions to adult, general critical care units in England, Wales and Northern Ireland: the Intensive Care National Audit & Research Centre Case Mix Programme Database

Table 2 Case mix, outcome and activity for all admissions in the Case Mix Programme Database (N = 129,647)

		N*	Mean/median/n	(SD/IQR/%)
Case mix
Mean (SD) age (years)		129,641	58.7	(19.8)
Median (IQR) age (years)		129,641	63	(47–73)
Gender male (n [%])		129,643	76,072	(58.7)
APACHE II^†
Mean (SD) Acute Physiology Score		102,239	12.5	(6.7)
Mean (SD) APACHE II score		102,237	16.5	(7.4)
Mean (SD) UK mortality probability		99,281	0.255	(0.222)
Median (IQR) UK mortality probability		99,281	0.181	(0.084–0.375)
Surgical status (n [%])		129,604
Nonsurgical			71,473	(55.1)
Elective/scheduled surgery			33,649	(26.0)
Emergency/urgent surgery			24,270	(18.7)
Surgery, unknown classification			212	(0.2)
Outcome ^‡
Mortality (n [%])
CMP unit		123,610	25,142	(20.3)
Any critical care unit		121,977	26,238	(21.5)
Hospital housing CMP unit		122,062	34,912	(28.6)
Any hospital		119,807	36,937	(30.8)
Activity
Median (IQR) length of stay (days)
CMP unit	Survivors	102,826	1.7	(0.8–4.0)
	Nonsurvivors	26,344	2.0	(0.7–6.1)
Any critical care unit	Survivors	99,896	2	(1–5)
	Nonsurvivors	27,133	2	(1–7)
Hospital housing CMP unit	Survivors	90,704	14	(7–27)
	Nonsurvivors	36,991	8	(2–19)
Any hospital	Survivors	85,761	16	(9–33)
	Nonsurvivors	38,651	9	(3–22)

APACHE, Acute Physiology and Chronic Health Evaluation; CMP, Case Mix Programme; IQR, interquartile range; SD, standard deviation. * Number of nonmissing and nonexcluded observations. ^† Exclusions: aged younger than 16 years, unit stay less than 8 hours, admission for primary burns or coronary artery bypass grafting, readmission within the same hospital stay, direct transfer in from another critical care unit, missing all 12 physiology variables. ^‡ Exclusions: readmission to the CMP unit within the same hospital stay.

ISSN: 1364-8535