Table 3.
Relative Transplant-Free Survival in Patients With CF and FEV1 < 30% Predicted: Univariate Cox Proportional Hazards Regression Results
| Covariate | HR (95% CI) |
|---|---|
| FEV1 % predicted, per 1% increasea | 0.94 (0.92-0.95)b |
| FEV1 % predicted, 5% intervalsa | 0.73 (0.68-0.78)b |
| Change in FEV1 % predicted, per 1% differencea,c | 1.00 (0.99-1.00) |
| Calendar year of first FEV1 < 30%a | 0.91 (0.89-0.93)b |
| Entry age, y | 1.00 (1.00-1.01) |
| Female sex | 1.39 (1.24-1.55)b |
| Height, in. | 0.95 (0.94-0.96)b |
| BMI ≤ 18 | 1.68 (1.49-1.90)b |
| F508del mutation status | |
| Homozygousd | 1.30 (1.03-1.65)e |
| Heterozygousd | 1.20 (0.95-1.53) |
| Unknownd | 2.06 (1.60-2.64)b |
| Pancreatic insufficiencyf | 1.05 (0.86-1.27) |
| No. pulmonary exacerbations a,g | 1.28 (1.24-1.31)b |
| 1 or more exacerbations (vs none)a | 1.99 (1.73-2.29)b |
| Supplemental oxygena,h | 2.96 (2.64-3.32)b |
| Any supplemental oxygena,i | 2.90 (2.59-3.25)b |
| Burkholderia cepaciaj | 1.99 (1.65-2.41)b |
| CFRD, on insulin | 1.70 (1.50-1.91)b |
| ESRD, on dialysis | 4.04 (2.53-6.45)b |
| Pneumothoraxk | 1.75 (1.22-2.49)e |
| Hemoptysis | 1.44 (1.04-1.98)e |
| Cirrhosis | 2.08 (1.59-2.74)b |
| Osteoporosis | 1.50 (1.26-1.80)b |
| Depression | 1.71 (1.53-1.92)b |
| Medicaid Insurance | 1.67 (1.50-1.87)b |
| High school graduatel | 0.78 (0.63-0.98)e |
| Whitem | 0.95 (0.72-1.26) |
| Marital status | |
| Marriedn | 0.74 (0.65-0.84)b |
| Living Togethern | 1.08 (0.87-1.34) |
| Noninvasive ventilationo | 3.14 (2.49-3.96)b |
| Smokingo | 1.41 (0.89-2.24) |
Covariates included in the multivariable analysis if P < .10.
CFRD = cystic fibrosis-related diabetes; ESRD = end-stage renal disease. See Table 1 legend for expansion of other abbreviation.
Violation of proportional hazards assumption.
P < .001.
Absolute difference in maximum FEV1 % predicted in the year prior to eligibility and the FEV1 % predicted at cohort entry.
Reference group has non-F508del mutations.
P < .10.
Pancreatic insufficiency defined as documentation of pancreatic enzyme use.
Number of exacerbations requiring IV antibiotics in the year prior to FEV1 <30%.
Continuous or nocturnal use of oxygen.
Any use of oxygen, including continuous, nocturnal, with exacerbations or PRN.
Sputum infection with Burkholderia cepacia complex.
Pneumothorax that required a chest tube.
High school graduate education or higher.
Race includes white, compared to non-white race.
Reference group is not married and not living together with a partner.
Noninvasive mechanical ventilation and smoking status were missing in > 50% of observations; missing values were imputed with “0,” which assumes a lack of ventilation and a lack of smoking, respectively, if it is not documented; these variables were not included in multivariate analyses due to high proportion missing data.