Table 2. Known-Groups Validity for T-VASI and F-VASI.
| Global assessment | Time | Extent of depigmentation, mean (SD) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| None | Limited | Moderate | Extensive | Very extensive | Overall F value | P value for pairwise comparisonsa | |||||||
| No. | VASI | No. | VASI | No. | VASI | No. | VASI | No. | VASI | ||||
| T-VASI | |||||||||||||
| Physician (PhGVA-T) | Baseline (n = 156) | 1 | 54.8 (NA) | 10 | 9.1 (3.8) | 69 | 12.6 (8.1) | 62 | 27.7 (15.6) | 14 | 48.9 (21.0) | 31.6 | 1: .03; 2: .04; 3: .37; 4: >.99; 5: .96; 6: <.01; 7: <.001; 8: <.001; 9: <.001; 10: <.001 |
| Week 24 (n = 157) | NA | NA | 12 | 7.1 (3.8) | 76 | 11.5 (7.9) | 59 | 26.7 (14.9) | 10 | 53.4 (22.8) | 48.5 | 5: .71; 6: <.001; 7: <.001; 8: <.001; 9: <.001; 10: <.001 | |
| Patient (PaGVA-T) | Baseline (n = 164) | 1 | 55.5 (NA) | 11 | 7.6 (4.4) | 60 | 13.2 (9.9) | 62 | 24.3 (14.2) | 30 | 38.8 (20.3) | 22.1 | 1: .03; 2: .06; 3: .29; 4: .84; 5: .82; 6: .01; 7: <.001; 8: <.01; 9: <.001; 10: <.001 |
| Week 24 (n = 160) | 1 | 26.6 (NA) | 20 | 11.2 (12.8) | 61 | 12.3 (10.9) | 56 | 23.7 (15.6) | 22 | 35.0 (21.3) | 12.8 | 1: .90; 2: .92; 3: >.99; 4: .99; 5: >.99; 6: .03; 7: <.001; 8: <.01; 9: <.001; 10: .06 | |
| F-VASI | |||||||||||||
| Physician (PhGVA-F) | Baseline (n = 159) | NA | NA | 14 | 0.6 (0.2) | 86 | 0.8 (0.4) | 43 | 1.40 (0.6) | 16 | 2.2 (0.7) | 45.0 | 5: .35; 6: <.001;7: <.001; 8: <.001; 9: <.001; 10: <.001 |
| Week 24 (n = 157) | 1 | 0 (NA) | 39 | 0.3 (0.2) | 74 | 0.8 (0.5) | 37 | 1.32 (0.6) | 6 | 2.4 (0.4) | 41.7 | 1: .98; 2: .61; 3: .10; 4: <.001; 5: <.001; 6: <.001; 7: <.001; 8: <.001; 9: <.001; 10: <.001 | |
| Patient (PaGVA-F) | Baseline (n = 164) | 1 | 1.4 (NA) | 35 | 0.6 (0.3) | 69 | 1.0 (0.5) | 44 | 1.38 (0.7) | 15 | 1.9 (0.7) | 18.4 | 1: .75; 2: .97; 3: >.99; 4: .93;5: .053; 6: <.001; 7: <.001; 8: <.01; 9: <.001; 10: .04 |
| Week 24 (n = 160) | 2 | 2.0 (0.3) | 40 | 0.6 (0.5) | 68 | 0.6 (0.5) | 40 | 1.10 (0.7) | 10 | 1.6 (0.8) | 11.4 | 1: .03; 2: .03; 3: .32; 4: .89; 5: >.99; 6: <.01; 7: <.001; 8: <.01; 9: <.001; 10: .33 | |
Abbreviations: F-VASI, Facial Vitiligo Area Scoring Index; NA, not applicable; PaGVA-F, Face Patient Global Vitiligo Assessment; PhGVA-F, Face Physician Global Vitiligo Assessment; T-VASI, Total Vitiligo Area Scoring Index; PaGVA-T, Total Physician Global Vitiligo Assessment; PhGVA-T, Total Physician Global Vitiligo Assessment.
a
Post hoc comparisons using Scheffe test to determine whether T-VASI and F-VASI scores discriminated between groups. Pairwise comparisons: 1, no vs limited; 2, no vs moderate; 3, no vs extensive; 4, no vs very extensive; 5, limited vs moderate; 6, limited vs extensive; 7, limited vs very extensive; 8, moderate vs extensive; 9, moderate vs very extensive; and 10, extensive vs very extensive.