Model 1 | Model 2 | Model 3: total effects | Model 4: direct effects | |||||||||
Ratio | GSE | P value | Ratio | GSE | P value | Ratio | GSE | P value | Ratio | GSE | P value | |
Diagnosis | ||||||||||||
AECOPD | 1.47 | 1.10 | <0.001 | 1.40 | 1.10 | <0.001 | 1.27 | 1.11 | 0.023 | 1.08 | 1.12 | 0.513 |
Pneumonia | 1.59 | 1.11 | <0.001 | 1.53 | 1.11 | <0.001 | 1.28 | 1.14 | 0.054 | 1.01 | 1.15 | 0.929 |
Other lung diseases | 1.40 | 1.19 | 0.047 | 1.31 | 1.18 | 0.107 | 1.06 | 1.24 | 0.775 | 0.96 | 1.24 | 0.839 |
Non-respiratory infection | 2.23 | 1.32 | 0.004 | 2.29 | 1.32 | 0.003 | 2.45 | 1.36 | 0.003 | 1.79 | 1.36 | 0.061 |
Circulatory diseases | 2.78 | 1.14 | <0.001 | 2.71 | 1.13 | <0.001 | 2.12 | 1.18 | <0.001 | 1.98 | 1.18 | <0.001 |
Cancer | 1.40 | 1.27 | 0.154 | 1.37 | 1.26 | 0.177 | 0.89 | 1.42 | 0.745 | 0.73 | 1.42 | 0.370 |
Digestive diseases | 1.21 | 1.28 | 0.442 | 1.21 | 1.27 | 0.438 | 1.45 | 1.27 | 0.123 | 1.32 | 1.27 | 0.242 |
Symptom diagnoses | 1.13 | 1.17 | 0.442 | 1.13 | 1.17 | 0.435 | 1.22 | 1.22 | 0.327 | 1.12 | 1.22 | 0.578 |
Other diagnoses | 1.59 | 1.16 | 0.002 | 1.56 | 1.16 | 0.003 | 1.40 | 1.41 | 0.326 | 1.22 | 1.41 | 0.556 |
Follow-up time in years | 1.13 | 1.03 | <0.001 | 1.12 | 1.03 | <0.001 | 1.11 | 1.04 | 0.004 | 1.12 | 1.04 | 0.004 |
Baseline covariates | ||||||||||||
Study group vs references | ||||||||||||
LTOT candidates | 1.31 | 1.26 | 0.246 | Omitted | ||||||||
Institutional | 0.96 | 1.19 | 0.836 | Omitted | ||||||||
Outpatients | 0.82 | 1.18 | 0.232 | 0.81 | 1.11 | 0.039 | ||||||
Outpatient clinic | 0.53 | 1.21 | 0.001 | Omitted | ||||||||
Covariates. baseline | ||||||||||||
Sex: female versus male | 0.63 | 1.09 | <0.001 | 1.00 | 1.09 | 0.978 | ||||||
Age in quartiles | 1.12 | 1.04 | 0.002 | 1.02 | 1.04 | 0.521 | ||||||
Pack-years in quartiles | 0.98 | 1.04 | 0.542 | 0.94 | 1.03 | 0.071 | ||||||
Hypertension: Y vs N | 1.24 | 1.08 | 0.009 | 0.94 | 1.08 | 0.420 | ||||||
Coronary artery disease: Y vs N | 1.10 | 1.18 | 0.576 | 1.19 | 1.29 | 0.491 | ||||||
Q-wave ECG: Y vs N | 1.04 | 1.16 | 0.783 | 1.01 | 1.14 | 0.962 | ||||||
Continuous baseline covariates in quartile | ||||||||||||
Creatinine | 1.14 | 1.04 | 0.002 | 1.02 | 1.04 | 0.522 | ||||||
Leucocytes | 1.07 | 1.04 | 0.072 | 1.07 | 1.04 | 0.056 | ||||||
C reactive protein | 1.02 | 1.04 | 0.615 | 1.04 | 1.03 | 0.199 | ||||||
FEV1 | 0.78 | 1.05 | <0.001 | 0.99 | 1.04 | 0.729 | ||||||
Arterial O2-tension | 0.89 | 1.05 | 0.018 | 0.94 | 1.04 | 0.114 | ||||||
High-sensitive cardiac troponin T | 1.93 | 1.04 | <0.001 | 1.87 | 1.03 | <0.001 | ||||||
Biomarkers during follow-up in quartiles | ||||||||||||
Leucocytes | 1.09 | 1.04 | 0.015 | |||||||||
C reactive protein | 1.08 | 1.04 | 0.038 | |||||||||
Creatinine | 1.06 | 1.03 | 0.052 | |||||||||
Arterial O2-tension | 1.01 | 1.03 | 0.823 | |||||||||
Heart rate | 1.08 | 1.03 | 0.028 |
AECOPD, acute exacerbation of chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; GSE, geometric SE; LTOT, long-term oxygen treatment.;