Table 2.
Comparison of cardiopulmonary scales and Saint George Respiratory Questionnaire between patients with rheumatoid arthritis and interstitial lung disease (RA-ILD) and patients with RA only.
| Variable | RA-ILD n = 39 |
RA only n = 42 |
P |
|---|---|---|---|
| Pulmonary symptoms | |||
| Cough, n (%)* | 31 (66.0) | 0 (0%) | — |
| Phlegm, n (%)* | 10 (21.3) | 0 (0%) | — |
| Wheezing, n (%)* | 3 (6.4) | 0 (0%) | — |
| Bilateral inspiratory/expiratory crackles, n (%)* | 33 (70.2) | 0 (0%) | — |
| Breathlessness, n (%)* | 19 (40.4) | 0 (0%) | — |
| Cardiopulmonary scales | |||
| 6MWT, meters | 310.0 (170.0–549.0) | 410.0 (270.0–549.0) | <0.001 |
| Pre-6MWT VAS modified Borg scale | 1.0 (0–3.1) | 0 (0–2.0) | — |
| Post-6MWT VAS modified Borg scale | 2.0 (0.5–8.0) | 1.0 (0–5.0) | <0.001 |
| Development of dyspnea, n (%) | 19 (23.8) | 7 (16.7) | 0.002 |
| SGRQ, % | |||
| Symptoms | 14.0 (0–30.0) | 3.0 (0–24.0) | <0.001 |
| Activity | 10.0 (0–38.0) | 4.0 (0–27.0) | <0.001 |
| Impact | 10.0 (0–38.0) | 3.5 (0–13.0) | <0.001 |
| Total | 13.0 (0–37.0) | 5.0 (0–25.0) | <0.001 |
| Lung function | |||
| FVC (% of predicted) | 71.0 (52.0–91.0) | 86.0 (80.0–99.0) | <0.001 |
| Restrictive patterns, n (%)* | 32 (68.1) | 0 (0%) | — |
Qualitative variables were expressed in frequency (%); quantitative variables were expressed in medians (ranges); FVC: forced vital capacity; 6MWT: six-minute walk test; VAS: visual analogue scale; SGRQ: Saint George Respiratory Questionnaire. *This variable is not accepted for evaluation by the program. P values were computed as follows: for quantitative variables with Mann-Whitney U test and for qualitative variables with chi-square (or Fisher exact test if required).