Table 2.
Bivariate analysis: association between study variables and utility values
| Variable | n (%) | Median (IQR) | P-value |
|---|---|---|---|
| Age (years) | 0.3 | ||
| ≤65 | 136 (39.3) | 0.80 (0.33) | |
| >65 | 210 (60.7) | 0.81 (0.25) | |
| Sex | 0.002 | ||
| Male | 296 (85.5) | 0.82 (0.25) | |
| Female | 50 (14.5) | 0.74 (0.44) | |
| Smoking status | 0.9 | ||
| Former smokers | 278 (80.3) | 0.81 (0.25) | |
| Current smokers | 68 (19.7) | 0.81 (0.27) | |
| Pack-years | 0.07 | ||
| ≤50 | 203 (58.7) | 0.82 (0.20) | |
| >50 | 143 (41.3) | 0.80 (0.30) | |
| Time from diagnosis (years) | 0.07 | ||
| ≤8 | 218 (63.0) | 0.82 (0.31) | |
| >8 | 128 (37.0) | 0.80 (0.25) | |
| BMIa | 0.4 | ||
| Underweight | 6 (1.7) | 0.69 (0.51) | |
| Normal | 98 (28.3) | 0.80 (0.31) | |
| Overweight | 141 (40.8) | 0.82 (0.25) | |
| Obese | 101 (29.2) | 0.81 (0.38) | |
| Comorbidities | |||
| Cardiovascular diseasesb | |||
| No | 252 (72.8) | 0.82 (0.25) | 0.2 |
| Yes | 94 (27.2) | 0.78 (0.30) | |
| Diabetes | 0.8 | ||
| No | 289 (83.5) | 0.81 (0.25) | |
| Yes | 57 (16.5) | 0.81 (0.38) | |
| Hematological malignancies | 0.8 | ||
| No | 303 (87.6) | 0.81 (0.27) | |
| Yes | 43 (12.4) | 0.80 (0.16) | |
| Charlson index | 0.2 | ||
| 0 | 165 (47.7) | 0.82 (0.25) | |
| 1 | 77 (22.3) | 0.82 (0.40) | |
| 2 | 62 (17.9) | 0.74 (0.26) | |
| 3+ | 42 (12.1) | 0.81 (0.31) | |
| FEV1 predictedc | <0.001 | ||
| Moderate | 135 (39.0) | 0.87 (0.22) | |
| Severe | 145 (41.9) | 0.80 (0.26) | |
| Very severe | 66 (19.1) | 0.66 (0.42) | |
| Positive bronchodilator test | 0.02 | ||
| No | 217 (84.1) | 0.81 (0.27) | |
| Yes | 41 (15.9) | 0.89 (0.20) | |
| Exacerbations in the previous year | <0.001 | ||
| No | 144 (41.6) | 0.87 (0.25) | |
| Yes | 202 (58.4) | 0.78 (0.31) | |
| Exacerbations in the previous year | <0.001 | ||
| <2 | 235 (67.9) | 0.84 (0.29) | |
| 2+ | 111 (32.1) | 0.74 (0.54) | |
| CAT total score | <0.001 | ||
| 0–10 | 74 (21.4) | 1.00 (0.13) | |
| 10–20 | 163 (47.1) | 0.84 (0.18) | |
| 20–30 | 87 (25.1) | 0.65 (0.45) | |
| 30–40 | 22 (6.4) | 0.28 (0.46) | |
| mMRC total score | <0.001 | ||
| <2 | 155 (44.8) | 0.91 (0.19) | |
| 2+ | 191 (55.2) | 0.71 (0.33) | |
Notes:
a
Underweight: <18.5 kg/m2; normal: 18.5–25 kg/m2; overweight: 25–30 kg/m2; and obese: ≥30 kg/m2.
b
Cardiovascular diseases are myocardial infarction, congestive heart failure, peripheral vascular disease, and cerebrovascular disease.
c
Post-bronchodilator. COPD moderate: FEV1/FVC <0.70 and 50%≤ FEV1 <80%; COPD severe: FEV1/FVC <0.70 and 30%≤ FEV1 <50%; COPD very severe: FEV1/FVC <0.70 and FEV1 <30%.
Abbreviations: BMI, body mass index; CAT, COPD Assessment Test; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; IQR, interquartile range; mMRC, modified Medical Research Council Dyspnea Scale; COPD, chronic obstructive pulmonary disease.