Univariate | Multivariate predictive | |||||
HR | 95% CI | P values | HR | 95% CI | P values | |
Predictive variables | ||||||
Age | 1.001 | 0.98 to 1.02 | 0.9 | |||
Male gender | 0.78 | 0.50 to 1.23 | 0.28 | |||
Zubrod 2–4 vs 0–1 | 3.59 | 2.22 to 5.80 | <0.001 | 3.71 | 2.14 to 6.45 | <0.001 |
Urgent/emergent vs elective | 1.51 | 0.89 to 2.56 | 0.13 | |||
Time from diagnosis to procedure (weeks) | 1 | 1.00 to 1.00 | 0.18 | |||
Baseline Borg | 1.15 | 1.07 to 1.25 | <0.001 | 1.11 | 1.01 to 1.21 | 0.03 |
Baseline utility | 2.31 | 0.45 to 11.83 | 0.32 | |||
Comorbidities | ||||||
COPD | 0.74 | 0.38 to 1.44 | 0.38 | |||
Cardiovascular | 1.62 | 0.98 to 2.67 | 0.06 | |||
Diabetes | 0.85 | 0.49 to 1.45 | 0.54 | |||
Second primary | 1.57 | 0.83 to 2.99 | 0.17 | |||
Cancer type | ||||||
Lung | 0.93 | 0.59 to 1.46 | 0.75 | |||
Other malignancies | <ref> | |||||
Initial treatment type | ||||||
Surgery | 1.39 | 0.74 to 2.61 | 0.3 | 1.99 | 0.99 to 4.02 | 0.05 |
Chemotherapy | 2.6 | 1.35 to 5.00 | 0.004 | 2.93 | 1.41 to 6.09 | 0.004 |
Radiation therapy | 2.44 | 1.13 to 5.24 | 0.02 | 2.02 | 0.86 to 4.79 | 0.11 |
No treatment | <ref> | <ref> | ||||
Any prior therapeutic bronchoscopy | 0.38 | 0.14 to 1.04 | 0.06 | |||
Indication(s) for therapeutic bronchoscopy | ||||||
Tracheoesophageal fistula | 1.19 | 0.37 to 3.80 | 0.77 | |||
Haemoptysis | 0.62 | 0.35 to 1.11 | 0.11 | |||
Number of bronchopulmonary segments obstructed | 1.05 | 1.01 to 1.10 | 0.03 | |||
Location of most proximal obstruction | ||||||
Trachea | 1.58 | 0.75 to 3.32 | 0.23 | |||
Bilateral mainstem | 2.11 | 0.77 to 5.77 | 0.15 | |||
Right mainstem | 1.11 | 0.54 to 2.31 | 0.78 | |||
Left mainstem | 0.78 | 0.34 to 1.78 | 0.56 | |||
Right bronchus intermedius | 1.19 | 0.50 to 2.80 | 0.7 | |||
Lobar only | <ref> | |||||
Obstruction type of most proximal location | ||||||
Endobronchial | <ref> | <ref> | ||||
Extrinsic | 2.01 | 1.21 to 3.32 | 0.01 | 2.66 | 1.53 to 4.62 | 0.001 |
Mixed | 3.31 | 1.68 to 6.54 | 0.001 | 1.82 | 0.82 to 4.03 | 0.139 |
Explanatory variables | ||||||
Ventilation type | ||||||
Jet ventilation | 1.59 | 0.69 to 3.66 | 0.27 | |||
Volume cycled | 0.61 | 0.27 to 1.42 | 0.25 | |||
Bronchoscopy type | ||||||
Rigid and flexible | 1.23 | 0.53 to 2.83 | 0.63 | |||
Flexible only | <ref> | |||||
Treatment modalities | ||||||
Any laser | 0.48 | 0.24 to 0.95 | 0.04 | |||
Electrocautery | 0.67 | 0.40 to 1.10 | 0.11 | |||
Argon plasma | 0.85 | 0.54 to 1.33 | 0.48 | |||
Cryorecanalisation | 0.73 | 0.41 to 1.31 | 0.29 | |||
Microdebrider | 0.78 | 0.46 to 1.32 | 0.35 | |||
Rigid ‘coring’ | 0.79 | 0.38 to 1.64 | 0.52 | |||
Dilation | 1.42 | 0.83 to 2.43 | 0.2 | |||
Stent type placed | ||||||
Aero | 1.17 | 0.50 to 2.73 | 0.71 | |||
Y-Stent | 0.8 | 0.33 to 1.94 | 0.63 | |||
Technical success | ||||||
Complete or partial | 0.69 | 0.34 to 1.38 | 0.3 | |||
Failed | <ref> | |||||
Postprocedure treatment | ||||||
Chemotherapy | 0.54 | 0.34 to 0.84 | 0.01 | |||
Radiation therapy | 0.86 | 0.55 to 1.35 | 0.52 | |||
Time-varying covariates | ||||||
Presence of stent | 2.47 | 1.56 to 3.91 | <0.001 | |||
Utility | 0.002 | 0.0003 to 0.011 | <0.001 | |||
Borg score | 1.22 | 1.14 to 1.31 | <0.001 | |||
Lower respiratory tract infection | 2.35 | 0.72 to 7.63 | <0.001 |
Utility range is from 0 to 1. So for a 0.01 unit increase in utility as a time-varying covariate, the HR is 0.002^0.01=0.94. So for each 0.01 increase in utility, the hazard rate of death decreases by 6%. Note that this is exponential, so for a 0.1 increase in utility, the hazard rate of death does not decrease by 60%. Rather it is 0.002^0.1=0.54. So an increase in utility of 0.1 is associated with a 46% decrease in the hazard rate of death.