Table 3.

Parsimonious analysis for factors associated with hospital stay at index admission

Variable	RR 95% CI	P value
Age, per 5 years	1.01 (0.997 to 1.03)	0.126
Pre-FEV1	0.97 (0.95 to 1.00)	0.055
VTE	1.40 (1.09 to 1.78)	0.007*
Hypoxic-hypercarbic encephalopathy	1.53 (1.07 to 2.18)	0.020*
Respiratory infection	1.11 (1.01 to 1.23)	0.040*
Osteoporosis	1.42 (1.05 to 1.91)	0.021*
Emergency admission	1.06 (0.98 to 1.14)	0.147

*P<0.05.

†

Pre-FEV1, Pre-bronchodilator forced expiratory volume in one second.; VTE, venous thromboembolism.