Table 2.
Symptoms, clinical and laboratory findings, and cognitive test results among COVID-19 cases and non-COVID controls.
| COVID-19 cases | Non-COVID controls | p-valuea | |
|---|---|---|---|
| Reported symptoms | |||
| Fatigue and post-exertional malaise | |||
| Chalder fatigue score -mean (SD) | 16.2 (5.7) | 13.5 (4.6) | <0.001 |
| Confidence interval | 15.6 to 16.8 | 12.6 to 14.4 | |
| Post exertional malaise score, -median (iqr) | 20.0 (5.0–45.0) | 10.0 (5.0–25.0) | 0.001 |
| Confidence interval | 15 to 25 | 10 to 15 | |
| Cognitive symptoms | |||
| Concentration difficulty, score -mean (SD) | 2.6 (1.4) | 2.7 (1.1) | 0.34 |
| Confidence interval | 2.4 to 2.7 | 2.5 to 2.9 | |
| Difficulty making decisions, score -mean (SD) | 1.9 (1.2) | 2.2 (1.3) | 0.01 |
| Confidence interval | 1.7 to 2.0 | 2.0 to 2.5 | |
| Memory difficulty, score -mean (SD) | 1.9 (1.1) | 2.1 (1.2) | 0.07 |
| Confidence interval | 1.8 to 2.0 | 1.9 to 2.3 | |
| Feeling confused or disoriented, score -mean (SD) | 1.4 (0.9) | 1.4 (0.7) | 0.34 |
| Confidence interval | 1.4 to 1.5 | 1.2 to 1.4 | |
| Sleep | |||
| Karolinska sleep questionnaire, -mean (SD) | 4.0 (1.2) | 3.9 (0.9) | 0.21 |
| Confidence interval | 3.9 to 4.1 | 3.7 to 4.1 | |
| Insomnia, -mean (SD) | 4.2 (1.3) | 4.0 (1.1) | 0.17 |
| Confidence interval | 4.1 to 4.3 | 3.8 to 4.2 | |
| Awakening problems, -mean (SD) | 3.7 (1.5) | 3.6 (1.2) | 0.45 |
| Confidence interval | 3.5 to 3.8 | 3.3 to 3.8 | |
| Sleepiness, -mean (SD) | 4.1 (1.3) | 4.1 (1.0) | 0.59 |
| Confidence interval | 4.0 to 4.3 | 3.9 to 4.3 | |
| Pain | |||
| Headache, score -mean (SD) | 2.5 (1.3) | 2.2 (1.1) | 0.07 |
| Confidence interval | 2.4 to 2.6 | 2.0 to 2.6 | |
| Brief pain inventory total score, mean (SD) | 10.2 (5.4) | 10.8 (4.7) | 0.29 |
| Confidence interval | 9.6 to 10.7 | 9.8 to 11.7 | |
| Worst pain in 24 h, mean (SD) | 3.9 (2.3) | 4.5 (2.3) | 0.02 |
| Confidence interval | 3.7 to 4.1 | 4.0 to 4.9 | |
| Least pain in 24 hours, mean (SD) | 1.7 (1.4) | 1.6 (0.9) | 0.28 |
| Confidence interval | 1.6 to 1.9 | 1.4 to 1.7 | |
| Pain on average, mean (SD) | 2.7 (1.7) | 3.0 (1.6) | 0.07 |
| Confidence interval | 2.5 to 2.9 | 2.7 to 3.4 | |
| Pain right now, mean (SD) | 1.8 (1.5) | 1.7 (1.2) | 0.35 |
| Confidence interval | 1.7 to 1.9 | 1.4 to 1.9 | |
| Neurological findings and brain injury biomarkers | |||
| Neurological examination, any findings -No. (%) | 6 (3) | 1 (1) | 0.33b |
| Neurofilament light chain, pg/mL, median (iqr) | 4.2 (3.3–5.3) | 3.8 (3.1–5.0) | 0.05c |
| Confidence interval | 4.0 to 4.4 | 3.6 to 4.1 | |
| Glial fibrillary acidic protein, pg/mL, median (iqr) | 61.1 (46.2–77.7) | 54.4 (41.0–69.8) | 0.01c |
| Confidence interval | 58.9 to 64.0 | 49.1 to 59.2 | |
| Cognitive test results | |||
| Digit span forward, total sum score -mean (SD) | 5.7 (2.0) | 5.6 (1.8) | 0.80 |
| Confidence interval | 5.5 to 5.9 | 5.3 to 6.0 | |
| Digit span backward, total sum score -mean (SD) | 9.4 (2.2) | 9.4 (2.3) | 0.84 |
| Confidence interval | 9.2 to 9.6 | 8.9 to 9.8 | |
| Digit span summary score, -mean (SD) | 15.1 (3.6) | 15.0 (3.4) | 0.79 |
| Confidence interval | 14.7 to 15.4 | 14.3 to 15.6 | |
| Hopkins verbal learning test-r evised |
|||
| HVLT-R, immediate recall, total sum score -mean (SD) | 24.6 (4.2) | 24.3 (3.9) | 0.44 |
| Confidence interval | 24.2 to 25.0 | 23.5 to 25.0 | |
| HVLT-R, delayed recall, total sum score -mean (SD) | 8.7 (2.1) | 8.4 (1.9) | 0.18 |
| Confidence interval | 8.5 to 8.9 | 8.0 to 8.8 | |
| HVLT-R correct recognition, mean (SD) | 11.6 (0.6) | 11.6 (0.8) | 0.41 |
| Confidence interval | 11.6 to 11.7 | 11.5 to 11.8 | |
| HVLT-R false recognition, mean (SD) | 0.3 (0.6) | 0.4 (0.8) | 0.42 |
| Confidence interval | 0.25 to 0.37 | 0.21 to 0.53 | |
a
Independent sample t-test unless otherwise stated;
b
Chi-square test;
c
Wilcoxon rank-sum test.