Exploring the impact of number and type of comorbidities on the risk of severe COPD exacerbations in Korean Population: a Nationwide Cohort Study

Table 3 Adjusted odds ratios for severe exacerbations of COPD relative to the number of comorbid diseases or comorbid groups in both cohorts

	Univariate analysis			Multivariable analysis for no. of comorbid diseases			Multivariable analysis for no. of comorbidity groups
	OR	95% CI	p	OR	95% CI	p	OR	95% CI	p
Entire cohort*
No. of comorbid diseases (range, 0–12)
0	Ref		< 0.001	Ref		0.019
1 or 2	1.35	(1.11 to − 1.65)		1.24	(1.01 to − 1.53)
3 or 4	1.54	(1.25 to − 1.89)		1.35	(1.09 to − 1.68)
≥ 5	1.87	(1.50 to − 2.32)		1.40	(1.12 to − 1.77)
No. of comorbidity groups (range, 0–5)***
0	Ref		< 0.001				Ref		0.001
1 or 2	1.34	(1.10 to − 1.62)					1.22	(1.00 to − 1.49)
3 or 4	1.70	(1.39 to − 2.08)					1.44	(1.16 to − 1.77)
5	3.26	(1.77 to − 5.99)					2.20	(1.16 to − 4.18)
Health-screening cohort**
No. of comorbid diseases (range, 0–12)
0	Ref		0.004	Ref		0.002
1 or 2	1.59	(1.09 to − 2.31)		1.63	(1.22 to − 2.17)
3 or 4	1.82	(1.24 to − 2.67)		1.77	(1.31 to − 2.38)
≥ 5	2.04	(1.36 to − 3.07)		1.78	(1.28 to − 2.46)
No. of comorbidity groups (range, 0–5)***
0	Ref		< 0.001				Ref		0.001
1 or 2	1.63	(1.13 to − 2.36)					1.68	(1.26 to − 2.23)
3 or 4	1.96	(1.34 to − 2.87)					1.81	(1.35 to − 2.44)
5	5.59	(2.08 to − 14.98)					2.23	(1.01 to − 4.93)

CI, confidence interval; ICS, inhaled corticosteroid; LABA, long-acting beta-2 agonist; LAMA, long-acting muscarinic antagonist; Ref., reference
*The final multivariate models were adjusted for sex, age, health insurance type, and COPD medication use (methylxanthines, ICS, LABA, and LAMA)
**The final multivariable models were adjusted for sex, age, COPD medication use (ICS, LABA, LAMA), body mass index, total cholesterol, and smoking status
***Each comorbid disease was grouped according to the affected organ system or disease mechanism

ISSN: 1471-2466