Table 2.
Symptoms, exercise capacity, and health-related quality of life at follow-up according to severity scale
| Total (n=1733) |
Seven-category scale |
OR or β (95% CI) |
|||||
|---|---|---|---|---|---|---|---|
| Scale 3: not requiring supplemental oxygen (n=439) | Scale 4: requiring supplemental oxygen (n=1172) | Scale 5–6: requiring HFNC, NIV or IMV (n=122) | Scale 4 vs 3 | Scale 5 −6 vs 3 | |||
| Symptoms | |||||||
| Any one of the following symptoms | 1119/1650 (68%) | 295/419 (70%) | 722/1111 (65%) | 102/120 (85%) | OR 0·77 (0·59 to 1·00) | OR 2·74 (1·42 to 5·30)* | |
| Fatigue or muscle weakness | 855/1654 (52%) | 218/419 (52%) | 547/1115 (49%) | 90/120 (75%) | OR 0·87 (0·68 to 1·11) | OR 2·75 (1·61 to 4·69)† | |
| Sleep difficulties | 437/1655 (26%) | 115/419 (27%) | 280/1116 (25%) | 42/120 (35%) | OR 0·89 (0·68 to 1·17) | OR 1·70 (1·03 to 2·81)* | |
| Hair loss | 359/1655 (22%) | 93/419 (22%) | 236/1116 (21%) | 30/120 (25%) | OR 1·01 (0·76 to 1·36) | OR 1·46 (0·84 to 2·55) | |
| Smell disorder | 176/1655 (11%) | 45/419 (11%) | 112/1116 (10%) | 19/120 (16%) | OR 0·95 (0·64 to 1·41) | OR 1·33 (0·66 to 2·69) | |
| Palpitations | 154/1655 (9%) | 43/419 (10%) | 96/1116 (9%) | 15/120 (13%) | OR 0·86 (0·57 to 1·31) | OR 1·50 (0·72 to 3·13) | |
| Joint pain | 170/1649 (10%) | 57/420 (14%) | 94/1110 (8%) | 19/119 (16%) | OR 0·53 (0·37 to 0·77)† | OR 0·77 (0·40 to 1·50) | |
| Decreased appetite | 138/1655 (8%) | 42/419 (10%) | 82/1116 (7%) | 14/120 (12%) | OR 0·67 (0·44 to 1·01) | OR 1·15 (0·55 to 2·43) | |
| Taste disorder | 120/1655 (7%) | 33/419 (8%) | 77/1116 (7%) | 10/120 (8%) | OR 0·89 (0·57 to 1·41) | OR 0·98 (0·42 to 2·30) | |
| Dizziness | 101/1655 (6%) | 33/419 (8%) | 61/1116 (5%) | 7/120 (6%) | OR 0·76 (0·48 to 1·21) | OR 1·00 (0·40 to 2·54) | |
| Diarrhoea or vomiting | 80/1652 (5%) | 30/418 (7%) | 45/1114 (4%) | 5/120 (4%) | OR 0·51 (0·30 to 0·85)* | OR 0·27 (0·08 to 0·86)* | |
| Chest pain | 77/1649 (5%) | 20/420 (5%) | 53/1110 (5%) | 4/119 (3%) | OR 0·96 (0·55 to 1·68) | OR 0·67 (0·21 to 2·22) | |
| Sore throat or difficult to swallow | 69/1655 (4%) | 28/419 (7%) | 36/1116 (3%) | 5/120 (4%) | OR 0·50 (0·29 to 0·86)* | OR 0·59 (0·18 to 1·89) | |
| Skin rash | 47/1655 (3%) | 15/419 (4%) | 28/1116 (3%) | 4/120 (3%) | OR 0·58 (0·29 to 1·14) | OR 0·54 (0·14 to 2·13) | |
| Myalgia | 42/1649 (3%) | 13/420 (3%) | 24/1110 (2%) | 5/119 (4%) | OR 0·75 (0·36 to 1·55) | OR 1·95 (0·59 to 6·46) | |
| Headache | 34/1649 (2%) | 9/420 (2%) | 22/1110 (2%) | 3/119 (3%) | OR 0·95 (0·42 to 2·12) | OR 1·65 (0·38 to 7·07) | |
| Low-grade fever | 2/1655 (<1%) | 0 | 2/1116 (<1%) | 0 | NA | NA | |
| mMRC score | |||||||
| 0 | 1195/1614 (74%) | 323/425 (76%) | 801/1078 (74%) | 71/111 (64%) | 1 (ref) | 1 (ref) | |
| ≥1 | 419/1614 (26%) | 102/425 (24%) | 277/1078 (26%) | 40/111 (36%) | OR 1·11 (0·84 to 1·47) | OR 2·18 (1·30 to 3·65)* | |
| EQ-5D-5L questionnaire‡ | |||||||
| Mobility: problems with walking around | 113/1621 (7%) | 25/426 (6%) | 72/1083 (7%) | 16/112 (14%) | OR 1·06 (0·63 to 1·78) | OR 2·46 (1·11 to 5·44)* | |
| Personal care: problems with washing or dishing | 11/1621 (1%) | 0 | 10/1083 (1%) | 1/112 (1%) | NA | NA | |
| Usual activity: problems with usual activity | 25/1610 (2%) | 5/425 (1%) | 15/1075 (1%) | 5/110 (5%) | OR 1·10 (0·35 to 3·50) | OR 3·39 (0·73 to 15·68) | |
| Pain or discomfort | 431/1615 (27%) | 111/422 (26%) | 274/1081 (25%) | 46/112 (41%) | OR 0·87 (0·66 to 1·13) | OR 1·96 (1·20 to 3·20)* | |
| Anxiety or depression | 367/1616 (23%) | 98/425 (23%) | 233/1080 (22%) | 36/111 (32%) | OR 0·88 (0·66 to 1·17) | OR 1·76 (1·05 to 2·96)* | |
| Quality of life§ | 80·0 (70·0 to 90·0) | 80·0 (70·0 to 90·0) | 80·0 (75·0 to 90·0) | 80·0 (70·0 to 87·5) | β 2·68 (−1·55 to 6·90) | β −2·35 (−10·60 to 5·94) | |
| Distance walked in 6 min, m | 495·0 (440·0 to 538·0) | 490·0 (448·5 to 535·0) | 495·0 (443·0 to 540·0) | 487·5 (412·0 to 525·0) | β 1·07 (−6·77 to 8·91) | β −35·30 (−51·00 to −19·60)† | |
| Percentage of predicted value¶ | 87·7 (79·1 to 95·8) | 86·3 (78·3 to 94·6) | 88·4 (80·1 to 96·6) | 81·5 (73·7 to 92·3) | β 0·48 (−1·13 to 2·10) | β −6·74 (−9·98 to −3·51)† | |
| Less than lower limit of the normal range‖ | 250/1689 (15%) | 74/428 (17%) | 144/1147 (13%) | 32/114 (28%) | OR 0·92 (0·65 to 1·31) | OR 4·33 (2·29 to 8·18)† | |
| eGFR<90 mL/min per 1·73 m2 | 487/1393 (35%) | 121/338 (36%) | 326/967 (34%) | 40/88 (45%) | OR 0·86 (0·63 to 1·19) | OR 1·44 (0·76 to 2·70) | |
Data are n/N (%) or median (IQR), unless otherwise specified. The differing denominators used indicate missing data. OR=odds ratio. HFNC=high-flow nasal cannula for oxygen therapy. NIV=non-invasive ventilation. IMV=invasive mechanical ventilation. NA=not applicable. mMRC=modified British Medical Research Council. EQ-5D-5L=EuroQol five-dimension five-level questionnaire. eGFR=estimated glomerular filtration rate.
p<0·05.
p<0·001.
Detailed results of EQ-5D-5L questionnaire are presented in the appendix (pp 12–13).
Quality of life was assessed using the EuroQol Visual Analogue Scale, ranging from 0 (worst imaginable health) to 100 (best imaginable health).
Predicted values were calculated according to the method of Enright and Sherrill.22
The lower limit of the normal range was calculated by subtracting 153 m from the predicted value for males or by subtracting 139 m for females.