Table 1 Intensive care units in the Case Mix Programme (CMP) participating and not participating in the COPD and Asthma Outcome Study (CMP data)
ParticipatingNot participating
Total number of units89 (100%)76 (100%)
Type of unit
    ICU41 (46.1%)27 (35.5%)
    ICU/HDU42 (47.2%)39 (51.3%)
    Other6 (6.7%)10 (13.2%)
Number of beds
    3–521 (23.6%)15 (19.7%)
    6–943 (48.3%)41 (53.9%)
    10+25 (28.1%)20 (26.3%)
In university or affiliated hospitals35 (39.7%)32 (42.1%)
Admissions per unit per year470454
Total admissions during study period (n1)39 30946 258
Admissions potentially eligible for study
    n2 (% of n1)1543 (3.9%)1501 (3.2%)
    Mean (SD) CAPS33.6 (12.0)35.1 (12.5)
    ICU survival (% of n2)1223 (79.3%)1138 (75.8%)
  • CAPS, COPD acute physiology score; HDU, high dependency unit; ICU, intensive care unit.