Table 1

Numbers of admissions in the Case Mix Programme Database meeting the exclusion criteria for Acute Physiology and Chronic Health Evaluation II (N = 129,647)

Exclusion criterion

n

%

Age at admission < 16 years

3658

2.8

Length of stay in unit < 8 hours

11,139

8.6

Admission for primary burns

238

0.2

Admission following coronary artery bypass grafting

1877

1.4

Readmission within the same hospital stay

6024

4.6

Transferred in from another critical care unit

5285

4.1

Missing all 12 physiological variables

1600

1.2

Total excluded (any of the above)

27,097

20.9

Harrison et al. Critical Care 2004 8:R99   doi:10.1186/cc2834