TABLE 2.
Socio‐demographic and clinical characteristics of participants per long COVID symptom trajectory group.
| Symptom trajectory number | p‐Value | |||||
|---|---|---|---|---|---|---|
| Total | 1 | 2 | 3 | 4 | ||
| N = 290 a | N = 70 | N = 137 | N = 59 | N = 24 | ||
| Baseline socio‐demographic and medical characteristics | ||||||
| Sex | <0.001 | |||||
| Male | 169 (58%) | 55 (79%) | 75 (55%) | 33 (56%) | 6 (25%) | |
| Female | 121 (42%) | 15 (21%) | 62 (45%) | 26 (44%) | 18 (75%) | |
| Age, years | 51.0 (36.0–62.0) | 46.5 (32.0–64.0) | 53.0 (39.0–64.0) | 51.0 (41.0–60.0) | 51.0 (42.5–55.0) | 0.47 |
| BMI category | 0.13 | |||||
| Normal weight | 121 (42%) | 38 (54%) | 56 (41%) | 20 (34%) | 7 (29%) | |
| Overweight | 101 (35%) | 23 (33%) | 47 (34%) | 21 (36%) | 10 (42%) | |
| Obese | 68 (23%) | 9 (13%) | 34 (25%) | 18 (31%) | 7 (29%) | |
| Migration background | 0.53 | |||||
| Dutch | 183 (63%) | 45 (64%) | 87 (64%) | 37 (63%) | 14 (58%) | |
| Non‐Dutch, OECD high‐income | 31 (11%) | 11 (16%) | 11 (8%) | 7 (12%) | 2 (8%) | |
| Non‐Dutch, OECD low/middle income | 69 (24%) | 12 (17%) | 34 (25%) | 15 (25%) | 8 (33%) | |
| Missing | 7 (2%) | 2 (3%) | 5 (4%) | 0 (0%) | 0 (0%) | |
| Smoking | 0.82 | |||||
| Non‐smoker | 181 (62%) | 45 (64%) | 83 (61%) | 38 (64%) | 15 (63%) | |
| Smoker | 19 (7%) | 2 (3%) | 11 (8%) | 5 (8%) | 1 (4%) | |
| Ex‐smoker | 87 (30%) | 22 (31%) | 41 (30%) | 16 (27%) | 8 (33%) | |
| Missing | 3 (1%) | 1 (1%) | 2 (1%) | 0 (0%) | 0 (0%) | |
| Highest level of education | 0.025 | |||||
| None, primary or secondary education | 41 (14%) | 8 (11%) | 24 (18%) | 6 (10%) | 3 (13%) | |
| Vocational training | 69 (24%) | 10 (14%) | 35 (26%) | 13 (22%) | 11 (46%) | |
| University education | 172 (59%) | 50 (71%) | 72 (53%) | 40 (68%) | 10 (42%) | |
| Missing | 8 (3%) | 2 (3%) | 6 (4%) | 0 (0%) | 0 (0%) | |
| Number of COVID‐19 high‐risk comorbidities b | 0.73 | |||||
| 0 | 160 (55%) | 40 (57%) | 76 (55%) | 32 (54%) | 12 (50%) | |
| 1 | 70 (24%) | 17 (24%) | 30 (22%) | 14 (24%) | 9 (38%) | |
| 2 | 36 (12%) | 6 (9%) | 20 (15%) | 7 (12%) | 3 (13%) | |
| 3 or more | 24 (8%) | 7 (10%) | 11 (8%) | 6 (10%) | 0 (0%) | |
| Follow‐up COVID‐19‐related characteristics | ||||||
| Hospital admission | 139 (48%) | 24 (34%) | 69 (50%) | 34 (58%) | 12 (50%) | 0.049 |
| ICU admission | 39 (13%) | 8 (11%) | 20 (15%) | 6 (10%) | 5 (21%) | 0.55 |
| Timing of infection | 0.051 | |||||
| First wave (up to 1 June 2020) | 98 (34%) | 24 (34%) | 51 (37%) | 21 (36%) | 2 (8%) | |
| Subsequent waves (from 1 June 2020 onwards) | 192 (66%) | 46 (66%) | 86 (63%) | 38 (64%) | 22 (92%) | |
| Vaccination status (primary series) | NA | |||||
| Not vaccinated | 24 (8%) | 3 (4%) | 8 (6%) | 8 (14%) | 5 (21%) | |
| Vaccinated | 231 (80%) | 59 (84%) | 109 (80%) | 47 (80%) | 16 (67%) | |
| LTFU before vaccination | 35 (12%) | 8 (11%) | 20 (15%) | 4 (7%) | 3 (13%) | |
| Died during follow‐up | 1 (0%) | 1 (1%) | 0 (0%) | 0 (0%) | 0 (0%) | 0.53 |
| Number of reinfections | 0.58 | |||||
| 0 | 231 (80%) | 57 (81%) | 112 (82%) | 45 (76%) | 17 (71%) | |
| 1 | 55 (19%) | 13 (19%) | 23 (17%) | 12 (20%) | 7 (29%) | |
| 2 or more | 4 (1%) | 0 (0%) | 2 (1%) | 2 (4%) | 0 (0%) | |
| Long COVID status at 12 weeks after illness onset | <0.001 | |||||
| No (recovered within 12 weeks) | 121 (42%) | 53 (76%) | 57 (42%) | 9 (15%) | 2 (8%) | |
| Yes (did not recover within 12 weeks) | 169 (58%) | 17 (24%) | 80 (58%) | 50 (85%) | 22 (92%) | |
Abbreviations: BMI, body mass index; COVID‐19, coronavirus disease 2019; ICU, intensive care unit; LTFU, lost to follow‐up; NA, not applicable; OECD, Organisation for Economic Co‐operation and Development.
Note: Continuous variables presented as median (IQR) and compared using the Kruskal–Wallis test; categorical and binary variables presented as n (%) and compared using the Pearson χ 2 test (or Fisher exact test if n < 5). Trajectory group membership was based on the maximum a posteriori probability of belonging to that group. Time‐dependent outcomes not compared between groups due to bias resulting from differing follow‐up lengths.
Two individuals could not be assigned to a trajectory group due to missing risk variable (BMI).
COVID‐related comorbidities are based on WHO Clinical Management Guidelines and include: cardiovascular disease (including hypertension), chronic pulmonary disease (excluding asthma), renal disease, liver disease, cancer, immunosuppression (excluding HIV, including previous organ transplantation), previous psychiatric illness and dementia.