Multivariate Cox proportional hazard stepwise analysis
| Parameters | RR (95% CI)# | p-value |
| Age | 1.10 (1.06–1.15) | <0.0005 |
| PSA | 3.61 (1.35–9.62) | 0.010 |
| Male sex | 3.42 (1.34–8.77) | 0.010 |
| LF criteria % pred | ||
| RV/TLC | 1.03 (1.01–1.04) | <0.0005 |
| TLC | 0.95 (0.93–0.98) | <0.0005 |
| KCO | 0.96 (0.94–0.98) | <0.0005 |
| Health-related quality of life questionnaire scores | ||
| SGRQ activities | 1.05 (1.02–1.08) | <0.0005 |
RR: relative rate; CI: confidence interval; PSA: Pseudomonas aeruginosa; LF: lung function; % pred: % predicted; RV: residual volume; TLC: total lung capacity; KCO: transfer coefficient for the lung for carbon monoxide; SGRQ: St George’s Respiratory Questionnaire. #: RR >1 describes a positive correlation between the parameter and mortality, whereas RR <1 suggests a negative correlation.