Table 2.
Comparison between the baseline characteristics according to survival status (survivors vs non-survivors) after 9 years
| Variable | Total (N=110) | Survivors (n=46) | Non-survivors (n=64) | P-value |
|---|---|---|---|---|
|
| ||||
| Male/female sex, n | 75/35 | 28/18 | 47/17 | 0.235a |
| Age, years | 65 (9.4) | 61.5 (8.7) | 67.6 (9) | <0.001b |
| SB, pack-years | 50 (34.7–70) | 43 (30–75) | 50 (40–69) | 0.616c |
| SpO2, % | 93 (92–96) | 94 (92.7–96) | 93 (91–95) | 0.035c |
| FEV1, % of the predicted | 52.5 (39–73.2) | 61 (46.5–79) | 46 (37–64.7) | 0.004c |
| FEV1, L | 1.21 (0.94–1.71) | 1.47 (0.99–1.92) | 1.10 (0.86–1.48) | 0.020c |
| BMI, kg/m2 | 25 (21–28) | 25.4 (22.3–28.6) | 24.5 (20.6–28) | 0.142c |
| Fat-free mass, kg | 41.6 (7.3–0.7) | 41 (7) | 42 (7.5) | 0.556b |
| mMRC, score | 1 (1–2) | 1 (1–2) | 2 (1–2) | 0.076c |
| 6MWT, m | 429 (94.2) | 461 (90.4) | 406 (90.6) | 0.002b |
| BODE, class | 1 (1–2) | 1 (1–1.2) | 2 (1–3) | <0.001c |
Notes: Parametric data are expressed as mean and SD and nonparametric as median (IQR 25–75).
a
Chi-squared test,
b
unpaired t-test, or
c
Mann–Whitney. BODE index: class 1 (score 0–2), class 2 (score 3 and 4), class 3 (score 5 and 6), and class 4 (score 7–10).
Abbreviations: 6MWT, 6-minute walk test; BMI, body mass index; BODE, Body mass index, airway Obstruction, Dyspnea, and Exercise capacity; SB, smoking burden; SpO2, pulse oximetry; mMRC, Modified Medical Research Council.