Table 4. Risk factors associated with occurred COPD exacerbation.

Risk factors		Odds ratio	95% CI	P value
History of pneumonia (ref = no)	Yes	18.09	8.86–36.94	<0.001
Total of CAT score (ref = CATSUM <10)	CATSUM ≥10	1.79	1.23–2.59	0.002
FEV1 (%)		0.98	0.97–0.99	<0.001
COPD exacerbation (ref <2)	Exacerbation ≥2	5.67	3.56–9.03	<0.001

Multivariate logistic regression model (P value <0.001). COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volumes in 1 second.