Cox analysis for mortality
Variable | n | HR | 95% CI | p-value |
Demographics | ||||
Age | 643 | 1.02 | 1.00–1.04 | 0.005 |
Male | 647 | 1.37 | 0.99–1.90 | 0.056 |
BMI | 469 | 0.92 | 0.88–0.96 | <0.001 |
Smoking | 579 | 1.64 | 1.15–2.35 | 0.006 |
Co-morbidities | ||||
Gastro-oesophageal reflux disease | 566 | 1.14 | 0.83–1.55 | 0.427 |
Pulmonary hypertension | 529 | 1.31 | 0.89–1.94 | 0.173 |
COPD | 552 | 1.33 | 0.97–1.83 | 0.078 |
Obstructive sleep apnoea | 562 | 1.12 | 0.73–1.73 | 0.607 |
Heart disease | 569 | 1.02 | 0.72–1.43 | 0.919 |
Diabetes mellitus | 568 | 0.92 | 0.62–1.34 | 0.657 |
Lung cancer | 566 | 0.88 | 0.12–6.29 | 0.898 |
Physiology# | ||||
FVC % pred¶ | 465 | 0.67 | 0.61–0.74 | <0.001 |
DLCO % pred¶ | 416 | 0.58 | 0.51–0.67 | <0.001 |
6MWT SpO2 at rest | 204 | 0.87 | 0.81–0.94 | <0.001 |
6MWT SpO2 nadir | 173 | 0.94 | 0.91–0.98 | <0.001 |
6MWT distance+ | 184 | 0.74 | 0.67–0.82 | <0.001 |
CPI¶ | 412 | 2.17 | 1.80–2.61 | <0.001 |
GAP stage | 412 | 4.64 | 3.33–6.47 | <0.001 |
Patient reported outcome measures | ||||
St George's Respiratory questionnaire | 568 | 1.03 | 1.02–1.04 | <0.001 |
UCSD shortness of breath questionnaire | 574 | 1.03 | 1.02–1.03 | <0.001 |
Anxiety score | 567 | 1.02 | 0.99–1.06 | 0.214 |
Depression score | 567 | 1.11 | 1.07–1.16 | <0.001 |
Cough severity | 509 | 1.01 | 1.00–1.14 | 0.030 |
Data in bold are statistically significant. BMI: body mass index; COPD: chronic obstructive pulmonary disease; FVC: forced vital capacity; DLCO: diffusion capacity for carbon monoxide; 6MWT: 6-min walk test; SpO2: arterial oxygen saturation measured by pulse oximetry; CPI: composite physiological index; GAP: gender, age, physiology. #: model adjusted for age, gender, BMI and smoking status with n indicating participants with results for all variables included in the model; ¶: every 10 unit change; +: every 50 m change.