Table 2. Diagnostic Performance of Direct Immunofluorescence for Bullous and Nonbullous Pemphigoid, by Biopsy Sitea.
| Biopsy Site | No. | % (95% CI) | Likelihood Ratio (95% CI) | Diagnostic OR (95% CI) | ||||
|---|---|---|---|---|---|---|---|---|
| Sensitivity | Specificity | PPV | NPV | Positive | Negative | |||
| Total Group | ||||||||
| Healthy skin | 480 | 80.7 (73.5-86.5) |
99.1 (97.3-99.8) |
97.7 (93.1-99.2) |
91.5 (88.6-93.7) |
87.4 (28.3-270.2) |
0.2 (0.1-0.3) |
447.2 (134.1-1491.8) |
| Perilesional skin | 629 | 90.4 (85.7-93.9) |
99.8 (98.7-100.0) |
99.5 (96.5-99.9) |
95.1 (92.9-96.7) |
371.4 (52.4-2631.7) |
0.1 (0.1-0.2) |
3846.2 (513.7-28 800.4) |
| Lesional skin | 373 | 76.2 (65.7-84.8) |
99.7 (98.1-100.0) |
98.5 (90.0-99.8) |
93.5 (90.8-95.5) |
220.2 (31.0-1563.6) |
0.2 (0.1-0.4) |
921.6 (121.5-6993.2) |
| Participants Without Skin Blisters | ||||||||
| Healthy skin | 253 | 74.5 (59.7-86.1) |
99.0 (96.5-99.9) |
94.6 (81.4-98.6) |
94.4 (91.3-96.5) |
76.7 (19.1-307.7) |
0.3 (0.2-0.4) |
297.5 (63.8-1386.8) |
| Perilesional skin | 281 | 78.1 (62.4-89.4) |
99.6 (97.7-100.0) |
97.0 (81.8-99.6) |
96.4 (93.7-97.9) |
187.3 (26.3-1333.3) |
0.2 (0.1-0.4) |
849.7 (104.2-6930.5) |
| Lesional skin | 254 | 68.4 (51.4-82.5) |
99.5 (97.5-100.0) |
96.3 (78.4-99.5) |
94.7 (91.8-96.6) |
147.8 (20.7-1057.0) |
0.3 (0.2-0.5) |
465.8 (58.2-3729.6) |
Abbreviations: NPV, negative predictive value; OR, odds ratio; PPV, positive predictive value.
a
Participants may have had biopsy specimens for DIF from different biopsy sites (1482 biopsy specimens were analyzed in 1125 patients).