Table 3.

Cox regression analysis to identify the predictors of mortality in the 9-year period

Variables	HR (95% CI), N=110	P-value
Male	1.34 (0.68–2.63)	0.390
Age (years)	0.98 (0.93–1.03)	0.610
SpO2 (%)	0.94 (0.85–1.04)	0.258
BODE index class 1 – reference	*	*
BODE index class 2	2.62 (1.36–5.04)	0.004
BODE index class 3	2.54 (1.15–5.61)	0.021
BODE index class 4	15.35 (3.11–75.75)	0.001
Charlson Comorbidity Index	1.29 (1.00–1.68)	0.049
Exacerbation (n)	1.32 (1.00–1.76)	0.048

Notes: All variables were included together in the Cox proportional hazard regression analysis (sex, age, SpO₂, BODE index, CCI, and number of exacerbations in the first 3 years). BODE exacerbation, number of exacerbations in the 3-year period of follow-up; index, class 1 (score 0–2), class 2 (score 3 and 4), class 3 (score 5 and 6), and class 4 (score 7–10).

Abbreviations: BODE, Body mass index, airway Obstruction, Dyspnea, and Exercise capacity; SpO₂, pulse oximetry.