Table 2.
Description of the sample used for the predictive analysis and coefficients estimate for elastic net regression predicting the presence of fatigue at 6 or 12 months follow-up (Fatigue Severity Scale corrected mean score). Levels of significance of the observed differences (Student's t-test and Chi-square) is reported both as p and q-value (false discovery rate corrected p-value). Patients self-rated their symptoms on the Beck's Depression Inventory (BDI); Zung Self-rating Depression Scale (ZSDS). Bold represents q < 0.05 and variable inclusion probability >85%.
| Predictors | Descriptive statistics |
Elastic net coefficients |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Total (n = 300) | Absence of long-term fatigue (n = 199) | Presence of long-term fatigue (n = 101) | t or χ2 | p-value | q-value | Coefficient | Standard deviation | 95% Lower CI | 95% Upper CI | Variable inclusion probability | |
| Intercept | 0.2748 | 0.0782 | 0.1215 | 0.4281 | 100.0 | ||||||
| BDI-13 mean score at one month follow-up | 3.267 ± 3.813 | 2.533 ± 3.078 | 4.713 ± 4.64 | −4.854 | <0.001 | <0.001 | 0.2010 | 0.1175 | −0.0292 | 0.4312 | 94.1 |
| ZSDS index mean score at one month follow-up | 43.959 ± 11.154 | 41.866 ± 9.467 | 48.084 ± 12.985 | −4.723 | <0.001 | <0.001 | 0.1659 | 0.1065 | −0.0430 | 0.3747 | 92.0 |
| Males Yes (%) | 201 (67%) | 148 (74%) | 53 (52%) | 14.528 | 0.001 | 0.002 | −0.0340 | 0.0296 | −0.0921 | 0.0240 | 81.1 |
| Under conventional antidepressant treatment Yes (%) | 37 (12%) | 15 (8%) | 22 (22%) | 12.573 | <0.001 | 0.002 | 0.0488 | 0.0439 | −0.0371 | 0.1348 | 80.3 |
| Positive psychiatric history Yes (%) | 71 (24%) | 38 (19%) | 33 (33%) | 6.836 | 0.009 | 0.017 | 0.0307 | 0.0310 | −0.0300 | 0.0914 | 73.1 |
| Body mass index | 27.953 ± 4.918 | 27.604 ± 4.401 | 28.641 ± 5.767 | −1.731 | 0.084 | 0.156 | 0.0929 | 0.0947 | −0.0927 | 0.2786 | 70.9 |
| Presence of organic comorbidity Yes (%) | 136 (45%) | 90 (45%) | 46 (46%) | 0.002 | 0.958 | 0.958 | 0.0506 | 0.0571 | −0.0614 | 0.1626 | 67.8 |
| Treated with cytokine blocking agents Yes (%) | 59 (20%) | 45 (23%) | 14 (14%) | 3.247 | 0.072 | 0.123 | −0.0211 | 0.0276 | −0.0753 | 0.0331 | 61.8 |
| Duration of hospitalization | 13.523 ± 11.23 | 14.271 ± 12.074 | 12.05 ± 9.225 | 1.624 | 0.105 | 0.164 | −0.0405 | 0.0614 | −0.1609 | 0.0798 | 52.6 |
| Oxygen saturation level at one month follow-up | 97.697 ± 1.093 | 97.704 ± 1.095 | 97.683 ± 1.095 | 0.152 | 0.879 | 0.958 | −0.0280 | 0.0545 | −0.1348 | 0.0788 | 49.9 |
| COVID-19 first wave Yes (%) | 93 (31%) | 57 (29%) | 36 (36%) | 1.534 | 0.251 | 0.354 | 0.0070 | 0.0195 | −0.0313 | 0.0453 | 45.8 |
| Hospitalized for acute COVID-19 Yes (%) | 266 (89%) | 177 (89%) | 89 (88%) | 0.45 | 0.831 | 0.95 | −0.0130 | 0.0312 | −0.0743 | 0.0482 | 45.3 |
| Caucasian Yes (%) | 280 (93%) | 189 (95%) | 91 (90%) | 2.559 | 0.109 | 0.164 | −0.0031 | 0.0356 | −0.0729 | 0.0667 | 42.3 |
| Intensive care unit for acute COVID-19 Yes (%) | 24 (8%) | 18 (9%) | 6 (6%) | 0.877 | 0.349 | 0.465 | −0.0075 | 0.0318 | −0.0698 | 0.0549 | 42.0 |
| Year of education | 12.77 ± 3.881 | 12.839 ± 3.706 | 12.634 ± 4.223 | 0.433 | 0.665 | 0.798 | 0.0016 | 0.0387 | −0.0742 | 0.0773 | 40.7 |
| Non invasive ventilation for acute COVID-19 Yes (%) | 76 (25%) | 52 (26%) | 24 (24%) | 0.198 | 0.656 | 0.798 | −0.0020 | 0.0204 | −0.0419 | 0.0380 | 38.1 |
| Age | 58.69 ± 11.748 | 58.653 ± 11.503 | 58.762 ± 12.274 | −0.076 | 0.94 | 0.958 | 0.0127 | 0.0484 | −0.0821 | 0.1075 | 37.7 |