Table 2.
Self-reported symptoms, comorbidities and quality of life, stratified by diagnostic criteria
| LLN+/FR+
|
LLN−/FR+
|
LLN−/FR−
|
|||
|---|---|---|---|---|---|
| N (%)a | p-valueψ | N (%)a | p-value$ | N (%)a | |
| Subjects | 527 | 324 | 1,753 | ||
| Symptoms | |||||
| Wheeze | 420 (80.5) | <0.001* | 221 (69.3) | 0.001* | 1,133 (65.6) |
| Sputum | 314 (60.9) | <0.001* | 141 (44.8) | 0.001* | 843 (49.3) |
| Dyspnea | 399 (75.7) | 0.063 | 231 (71.3) | 0.145 | 1,255 (71.6) |
| Cough | 309 (59.7) | 0.001* | 138 (41.4) | 0.001* | 743 (43.1) |
| Chr cough | 152 (28.8) | 0.002 | 67 (20.7) | 0.008 | 373 (21.3) |
| Chr sputum | 118 (22.4) | 0.001* | 49 (15.6) | 0.145 | 276 (15.7) |
| Comorbidities | |||||
| Heart disease | 36 (6.9) | 0.109 | 46 (14.2) | 0.001* | 159 (9.1) |
| Heart failure | 10 (1.9) | 0.086 | 13 (4.0) | 0.068 | 59 (3.4) |
| Hypertension | 205 (39.2) | 0.697 | 161 (49.7) | 0.003 | 699 (40.1) |
| Diabetes | 59 (11.3) | 0.022 | 58 (17.9) | 0.007 | 266 (15.3) |
| Stroke | 19 (3.6) | 0.129 | 20 (6.2) | 0.088 | 42 (2.4) |
| Depression | 114 (21.8) | 0.776 | 36 (11.1) | 0.001* | 390 (22.4) |
| Asthma | 163 (30.9) | <0.001* | 74 (22.8) | 0.009 | 322 (18.4) |
| mMRC dyspnoea | |||||
| Median (IQR) | 1 (1–2) | 0.002 | 1 (0–2) | 0.092 | 1 (0–2) |
| 0 | 120 (24.0) | 91 (29.1) | 486 (28.9) | ||
| 1 | 173 (34.5) | 111 (35.5) | 628 (37.3) | ||
| 2 | 87 (17.4) | 39 (12.5) | 227 (13.5) | ||
| 3 | 74 (14.8) | 46 (14.7) | 219 (13.0) | ||
| 4 | 47 (9.4) | 26 (8.3) | 122 (7.3) | ||
| CAT score | |||||
| Median (IQR) | 12 (7–19) | 0.001* | 10 (6–16) | 0.001* | 11 (6–16) |
| 0–10 | 205 (43.9) | 149 (53.6) | 756 (49.5) | ||
| 11–20 | 174 (37.3) | 91 (32.7) | 555 (36.4) | ||
| 21–30 | 71 (15.2) | 32 (11.5) | 187 (12.3) | ||
| 31–40 | 17 (3.6) | 6 (2.2) | 28 (1.8) | ||
| EQ-5D | |||||
| Median (IQR) | 0.80 (0.68–1.0) | 0.80 | 0.77 (0.64–0.91) | 0.013 | 0.80 (0.68–1.0) |
Notes:
a
Unless otherwise specified. Results for LLN−/FR+ were compared with LLN+/FR+ ($) and results for LLN+/FR+ were compared with LLN−/FR− (ψ) using Pearson chi-square tests.
*
p-values ≤0.001 are statistically significant in accordance with Bonferroni correction for multiple comparisons.
Abbreviations: CAT, COPD Assessment Test; Chr, chronic; EQ-5D, EuroQol-5D (measure of quality of life); FR, fixed ratio; IQR, interquartile range; LLN, lower limit of normal; mMRC, modified Medical Research Council score.