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Subgroup analysis of intervention duration.
| Duration group (weeks) | Number, n | Effective (yes), n (%) | Limited effect, n (%) | Not effective (no), n (%) |
| Ultrashort (≤1) | 4 | 2 (50.0) | 2 (50.0) | 0 (0) |
| Short (>1 and <8) | 16 | 10 (63) | 4 (25) | 2 (13) |
| Medium (8-16) | 18 | 12 (67) | 5 (28) | 1 (6) |
| Long (>16) | 4 | 3 (75) | 0 (0) | 1 (25) |
| Subtotal (analyzed) | 42 | 27 (64) | 11 (26) | 4 (10) |
| Excluded: not reported | 4 | N/Aa | N/A | N/A |
aN/A: not applicable.
