Table 3 Recruitment, baseline values, ventilation, survival and questionnaire response
Intubation not neededIntubatedNot to be intubated(n = 181)Overall(n = 832)p Value§
COPD±(n = 179)“Pure” asthma(n = 22)COPD±(n = 394)“Pure” asthma(n = 56)
Admitted directly to ICU* (%)60.377.399.5100.056.981.3
On admission
    Mean (SD) age (years)67.7 (9.2)59.1 (10.6)66.8 (8.9)57.9 (9.7)70.3 (9.4)67 (9.7)
    Mean (SD) CAPS23.9 (9.9)22.4 (10.6)31 (10.8)26.4 (9.8)26.4 (10.2)27.9 (10.8)
    Mean (SD) MAC27.7 (5)31.4 (5.2)28.9 (5.2)30.5 (5.3)27.4 (5.9)28.5 (5.4)
    House/bedbound (%)34.613.631.212.567.438.1
    On long-term oxygen† (%)12.99.110.45.438.116.6
Ventilation
    Non-invasive only (%)74.713.60.00.091.736.6<0.001
Median (IQR) length of stay (days)
    In ICU3 (1.5, 5)2 (1, 3)9 (4. 16)6.5 (3, 15)3 (1, 4)4 (2, 10)<0.001
    In hospital12 (7, 19)8.5 (6, 12)20 (10, 36)15 (8, 26)10 (5, 17)14 (8, 27)<0.001
Survival‡
    Surviving ICU/HDU (%)98.9 (96 to 99.9)100 (84.6 to 100)74.9 (70.3 to 79.1)89.3 (78.1 to 96.0)72.4 (65.3 to 78.7)81.1 (78.3 to 83.7)<0.001
    Surviving hospital (%)93.9 (89.3 to 96.9)95.5 (77.2 to 99.9)61.2 (56.2 to 66)85.7 (73.8 to 93.6)59.7 (52.1 to 66.9)70.4 (67.2 to 73.5)<0.001
    Surviving 180 days (%)81.6 (75.1 to 87)95.5 (77.2 to 99.9)54.6 (49.5 to 59.6)85.7 (73.8 to 93.6)48.1 (40.6 to 55.6)62.1 (58.7 to 65.4)<0.001
  • CAPS, COPD acute physiology score; HDU, high dependency unit; ICU, intensive care unit; IQR, interquartile range; MAC, mid-arm circumference.

  • *Not admitted to a respiratory support unit at any stage.

  • †Oxygen concentrator at home before admission.

  • ‡With exact 95% confidence intervals.

  • §χ2 test for percentages (independence in contingency tables); Kruskal-Wallis test for lengths of stay.