TABLE 3

Multivariate Cox regression analysis of factors associated with survival

VariableHazard ratio for death (95% CI)p-value
Chronic Pseudomonas aeruginosa infection0.98 (0.70–1.36)0.89
Age years1.05 (1.04–1.07)<0.001
Male sex versus female1.29 (0.99–1.67)0.06
MRC dyspnoea score1.25 (1.11–1.40)<0.001
FEV1 % predicted
 <301.00 (ref.)NA
 30–490.66 (0.43–0.99)0.05
 50–790.44 (0.29–0.68)<0.001
 ≥800.45 (0.28–0.73)0.001
Hospitalised exacerbations1.60 (1.17–2.19)0.003
Radiology score#1.02 (0.99–1.06)0.17
BMI <18.5 kg·m−21.70 (1.14–2.54)0.01
Smoking status1.14 (0.86–1.50)0.37
Exacerbations in the previous year per additional exacerbation1.06 (1.01–1.12)0.02
Chronic Haemophilus influenzae infection0.59 (0.40–0.86)0.007
Chronic Staphylococcus aureus infection1.69 (1.10–2.60)0.02
Chronic Moraxella catarrhalis infection0.72 (0.39–1.33)0.30
Chronic Enterobacteriaceae infection0.71 (0.44–1.15)0.16
COPD1.41 (1.04–1.90)0.03
Diabetes1.27 (0.92–1.75)0.14
Chronic renal failure1.46 (1.03–2.06)0.03
Ischaemic heart disease1.47 (1.12–1.93)0.006
Oral long-term antibiotic suppressive therapy1.11 (0.84–1.47)0.46
Nebulised long-term antibiotic suppressive therapy0.80 (0.51–1.25)0.33

MRC: Medical Research Council; FEV1: forced expiratory volume in 1 s; BMI: body mass index; COPD: chronic obstructive pulmonary disease; NA: not applicable. #: Reiff score.