Table 4. A cross-tabulation analysis of association between ventilatory support requirements and clinical severity indicators (CAT score and modified DECAF score).

Fisher's exact test was used instead of the chi-square test due to expected cell frequencies <5 in multiple cells. ^*Statistically significant at p-value less than 0.05

CAT: COPD Assessment Test; DECAF: Dyspnea, Eosinopenia, Consolidation, Acidemia, and Atrial Fibrillation; IMV: Invasive mechanical ventilation; BiPAP - Bi-level positive airway pressure; NIV: Non-invasive ventilation; COPD: Chronic obstructive pulmonary disease

Ventilatory Support Requirements versus Clinical Severity Indicators		Ventilation				Fischer’s exact value	p-value
		IMV (n = 29)	NIV (n = 14)	BiPAP (n = 19)	Room Air (n = 58)
CAT score	< 10 (n = 44)	10 (22.7%)	3 (6.8%)	5 (11.4%)	26 (59.1%)	10.268	0.113
	10 to 20 (n = 46)	7 (15.2%)	7 (15.2%)	10 (21.8%)	22 (47.8%)
	> 20 (n = 30)	12 (40%)	4 (13.3%)	4 (13.3%)	10 (33.4%)
Modified DECAF score	Low risk (n = 70)	3 (4.3%)	5 (7.1%)	8 (11.4%)	54 (77.1%)	125.237	0.001*
	Intermediate risk (n = 21)	0 (0%)	8 (38.1%)	9 (42.9%)	4 (19.0%)
	High risk (n = 29)	26 (89.7%)	1 (3.4%)	2 (6.9%)	0 (0%)