Table 3.
Results of post hoc comparison and ROC analysis of muscle excitability data of COVID‐19 patients with and without critical illness myopathy
| CIM+ (N = 17) | CIM− (N = 14) | P value | Adj. P value | AUC (95% CI) | Cut‐off | Sensitivity | Specificity | Accuracy | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Day 1 | ||||||||||
| MRRP (ms) | 6.6 (±2.3) | 5.0 (±1.3) | 0.025 | 0.049 | 0.721 (0.536; 0.906) | 6.065 | 0.588 | 0.929 | 0.742 | |
| ESN | 7.6 (±3.1) | 10.5 (±4.6) | 0.049 | 0.049 | 0.679 (0.470; 0.887) | 7.990 | 0.706 | 0.714 | 0.710 | |
| Lat(15 Hz)Last | 90.5 (±5.0) | 86.3 (±4.4) | 0.022 | 0.022 | 0.718 (0.534; 0.903) | 87.600 | 0.647 | 0.714 | 0.677 | |
| Lat(30 Hz)First | 102.2 (±4.0) | 98.4 (±4.1) | 0.013 | 0.022 | 0.734 (0.550; 0.919) | 102.650 | 0.562 | 0.857 | 0.700 | |
| Day 2 | ||||||||||
| MRRP (ms) | 5.9 (±1.9) | 4.6 (±1.4) | 0.056 | 0.056 | 0.752 (0.552; 0.953) | 4.765 | 0.875 | 0.769 | 0.828 | |
| ESN | 8.0 (±3.9) | 10.8 (±3.0) | 0.044 | 0.056 | 0.764 (0.566; 0.962) | 8.855 | 0.812 | 0.769 | 0.793 | |
| Lat(15 Hz)Last | 90.2 (±5.8) | 84.4 (±3.5) | 0.004 | 0.005 | 0.820 (0.652; 0.987) | 88.600 | 0.750 | 0.923 | 0.828 | |
| Lat(30 Hz)First | 102.5 (±4.2) | 97.7 (±3.9) | 0.005 | 0.005 | 0.777 (0.603; 0.951) | 99.750 | 0.800 | 0.692 | 0.750 | |
| Day 5 | ||||||||||
| MRRP (ms) | 5.5 (±2.6) | 4.9 (±1.9) | 0.476 | 0.476 | 0.625 (0.403; 0.847) | 4.620 | 0.625 | 0.692 | 0.655 | |
| ESN | 6.9 (±3.3) | 9.0 (±4.8) | 0.174 | 0.348 | 0.597 (0.377; 0.817) | 12.185 | 1.000 | 0.308 | 0.700 | |
| Lat(15 Hz)Last | 90.5 (±9.3) | 86.8 (±6.3) | 0.249 | 0.337 | 0.672 (0.466; 0.877) | 92.550 | 0.471 | 0.917 | 0.655 | |
| Lat(30 Hz)First | 101.5 (±10.1) | 98.6 (±3.8) | 0.337 | 0.337 | 0.728 (0.529; 0.927) | 101.200 | 0.706 | 0.833 | 0.759 | |
| Day 10 | ||||||||||
| MRRP (ms) | 6.2 (±1.7) | 4.3 (±1.1) | 0.002 | 0.002 | 0.824 (0.669; 0.978) | 4.350 | 0.941 | 0.643 | 0.806 | |
| ESN | 5.1 (±2.8) | 11.3 (±3.8) | 0.000 | 0.000 | 0.908 (0.799; 1.000) | 9.940 | 1.000 | 0.714 | 0.871 | |
| Lat(15 Hz)Last | 91.6 (±5.2) | 86.2 (±6.0) | 0.014 | 0.014 | 0.768 (0.579; 0.957) | 87.250 | 0.875 | 0.714 | 0.800 | |
| Lat(30 Hz)First | 104.2 (±5.9) | 97.4 (±4.3) | 0.002 | 0.004 | 0.857 (0.704; 1.000) | 100.350 | 0.846 | 0.857 | 0.852 | |
Data of post hoc comparisons using independent samples t‐tests are presented as mean (±standard deviation). Values are reported in percent if not differently indicated. P values were adjusted for multiple comparisons of parameters within one recording for all days separately (e.g. for MRRP and ESN of the muscle velocity recovery cycle on Day 1, and for MLat15 and MLatF30 of the frequency ramp on Day 1) using FDR method, and considered significant if <0.05.
AUC, area under the curve; CI, confidence interval; CIM, critical illness myopathy; ESN, early supernormality; Lat(15 Hz)Last, latency to the last response in train at 15 Hz; Lat(30 Hz)First, latency to the first response in train at 30 Hz; MRRP, muscle relative refractory period; ROC, receiver operator characteristic.