Table 3.

Multiple Cox Regression for Mortality of GOLD 2023 and GOLD 2017 Group in COPD

Variable	Crude HR (95% CI)	Crude P-value	Adjusted HR (95% CI)	Adjusted P-value
Model 1
GOLD 2023
Group A	Reference
Group B	6.91 (1.69–28.16)	0.007*	5.34 (1.30–21.94)	0.020*
Group E	9.49 (2.34–38.49)	0.002*	6.29 (1.53–25.79)	0.011*
Sex
Female	Reference
Male	1.33 (0.82–2.17)	0.249	1.37 (0.72–2.61)	0.333
Age	1.07 (1.05–1.09)	<0.001*	1.07 (1.05–1.09)	<0.001*
BMI	0.91 (0.87–0.95)	<0.001*	0.94 (0.90–0.99)	0.013*
Smoking status
Non-smoker	Reference
Current Smoker	1.12 (0.72–1.73)	0.622	0.92 (0.52–1.62)	0.771
Former Smoker	1.26 (0.8–1.99)	0.327	0.79 (0.44–1.41)	0.420
COPD severity
Stage 1	Reference
Stage 2	1.40 (0.73–2.66)	0.309	1.04 (0.54–1.99)	0.906
Stage 3	1.88 (0.99–3.56)	0.053	1.24 (0.65–2.38)	0.516
Stage 4	2.98 (1.53–5.81)	0.001*	2.01 (1.01–4.00)	0.047*
Model 2
GOLD 2017
Group A	Reference
Group B	6.91 (1.69–28.15)	0.007*	5.42 (1.32–22.25)	0.019*
Group C	2.94 (0.41–20.86)	0.281	3.10 (0.44–22.02)	0.258
Group D	9.94 (2.45–40.32)	0.001*	6.54 (1.59–26.87)	0.009*
Sex
Female	Reference
Male	1.33 (0.82–2.17)	0.249	1.37 (0.72–2.6)	0.340
Age	1.07 (1.05–1.09)	<0.001*	1.07 (1.05–1.09)	<0.001*
BMI	0.91 (0.87–0.95)	<0.001*	0.94 (0.90–0.99)	0.013*
Smoking status
Non-smoker	Reference
Current Smoker	1.12 (0.72–1.73)	0.622	0.93 (0.53–1.64)	0.811
Former Smoker	1.26 (0.80–1.99)	0.327	0.80 (0.44–1.44)	0.453
COPD severity
Stage 1	Reference
Stage 2	1.40 (0.73–2.66)	0.309	1.01 (0.53–1.93)	0.975
Stage 3	1.88 (0.99–3.56)	0.053	1.19 (0.62–2.28)	0.603
Stage 4	2.98 (1.53–5.81)	0.001*	1.91 (0.96–3.82)	0.067

Note: Adjusted for sex, age, BMI, smoking status, and GOLD severity. * Statistical significance was determined at a P-value less than 0.05.

Abbreviations: COPD, chronic obstructive pulmonary disease; BMI, body mass index; COPD severity and group was classified using Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria; HR, Hazard Ratio; CI, confidence interval.