Clinical variables predicting the risk of a hospital stay for longer than 7 days in patients with severe acute exacerbations of chronic obstructive pulmonary disease: a prospective study

Table 4 Study outcomes

Variables	Normal LHS (≤ 7 days) (n = 213)	Prolonged LHS (> 7 days) (n = 224)	p value
NIMV, %	11	31	< 0.001
IMV, %	0	7	< 0.001
ICU admission, %	5	19	< 0.001
Mortality at 6-months, %	4	14	< 0.001
Survival time	176.3 [173.8 to 178.8]	168.5 [164.3 to 172.7]	0.001
Cumulative mortality at 1-year, %	11	25	< 0.001
Survival time	342.5 [334.4 to 350.5]	313.6 [301.1 to 326.2]	< 0.001
Cumulative mortality at 3-years, %	37	48	0.036
Survival time	904.6 [862.3 to 946.8]	783.8 [730.6 to 837.1]	0.007

Data are shown as number of patients (percentage) and calculated for non-missing data
Survival time was calculated as mean [95% confidence interval] and reported as days
Abbreviations: NIMV and IMV indicate non-invasive and invasive mechanical ventilation, respectively; ICU, intensive care unit

ISSN: 1465-993X