Changes in COPD Assessment Test (CAT), Patient Health Questionnaire Depression Scale 9 (PHQ-9) and Modified Medical Research Council (mMRC) scores
| COSYCONET (1) | COVID 1 (2) | COVID 2 (3) | Mean change 1 to 2 | Mean change 2 to 3 | p-value 1 versus 2 “before/during” | p-value 2 versus 3 “during pandemic” | |
| CAT item | 17.1±6.9 | 18.0±7.5 | 18.5±7.6 | +0.90 | +0.05 | 0.0003 | 0.0417 |
| (1) Cough | 2.16±1.10 | 2.25±1.17 | 2.34±1.17 | +0.09 | +0.09 | 0.1272 | 0.0879 |
| (2) Sputum | 2.17±1.23 | 2.19±1.33 | 2.23±1.31 | +0.02 | +0.04 | 0.7937 | 0.5208 |
| (3) Chest tightness | 1.74±1.24 | 1.68±1.35 | 1.85±1.39 | −0.06 | +0.17 | <0.0001 | 0.0074 |
| (4) Dyspnoea/stairs | 3.59±1.27 | 3.77±1.30 | 3.78±1.36 | +0.18 | +0.01 | <0.0001 | 0.6409 |
| (5) Limitations/home activities | 2.10±1.47 | 2.35±1.59 | 2.44±1.59 | +0.25 | +0.09 | 0.0555 | 0.1212 |
| (6) Confidence leaving home | 0.80±1.17 | 1.16±1.52 | 1.14±1.47 | +0.36 | −0.02 | <0.0001 | 0.8585 |
| (7) Sleep | 2.00±1.43 | 2.03±1.55 | 2.12±1.51 | +0.03 | +0.09 | 0.1321 | 0.2743 |
| (8) Energy | 2.40±1.17 | 2.59±1.30 | 2.64±1.29 | +0.19 | +0.05 | <0.0001 | 0.4507 |
| mMRC | 1.47±0.91 | 1.62±0.97 | 1.70±1.01 | +0.15 | +0.08 | <0.0001 | 0.0673 |
| PHQ-9 | 5.63±4.27 | 5.98±4.92 | 6.16±4.65 | +0.35 | +0.18 | 0.0863 | 0.2318 |
| Healthy | 170 (54.8) | 173 (46.4) | 161 (45.1) | <0.0001 | <0.0001 | ||
| Clinically unremarkable | 142 (38.3) | 132 (35.4) | 122 (34.2) | ||||
| Mild depression | 43 (11.6) | 40 (10.7) | 52 (14.6) | ||||
| Moderate depression | 11 (3.0) | 19 (5.1) | 18 (5.0) | ||||
| Severe depression | 5 (1.4) | 9 (2.4) | 4 (1.1) |
Data expressed as n (%) and mean±sd unless otherwise stated. Comparison of changes of the single CAT items, the PHQ-9 as well as the mMRC between the pre-COVID COSYCONET visit and COVID1, as well as the comparison between the two COVID surveys during the pandemic. The level of significance was set at p<0.05. The comparisons between groups were performed using pairwise t-test for the metric variables. Additionally, the PHQ-9 categories were compared using Wilcoxon signed-rank tests for dependent samples.