Table 5.
Test–retest reliability of the PMMSA Scores
| Period 1* (N = 12) |
Period 2† (N = 28) |
|
|---|---|---|
| 4FS | 0.96 | 0.91 |
| Tiredness at rest | 0.88 | 0.81 |
| Tiredness during activities | 0.94 | 0.85 |
| Muscle weakness at rest | 0.90 | 0.90 |
| Muscle weakness during activities | 0.98 | 0.92 |
| Balance problems | 0.82 | 0.92 |
| Vision problems | 0.98 | 0.96 |
| Abdominal discomfort | 0.93 | 0.93 |
| Muscle pain | 0.94 | 0.95 |
| Numbness | 0.96 | 0.98 |
| Headache | 0.80 | 0.81 |
4FS = 4-item Fatigue Scale; PMMSA = Primary Mitochondrial Myopathy Symptom Assessment; TRT = test–retest
*Test–retest estimates were calculated as the Pearson correlation coefficients relating weekly scores generated during screening Week 1 (Days − 13 to − 7) and screening Week 2 (Days − 6 to 0)
†Test–retest estimates were calculated as the Pearson correlation coefficients relating weekly scores generated during Study Week 7 and Week 8 (last two weeks of the washout period)