Table 1 Clinical signs of clubbing compared with Gold standard measure
Clinical Sign | "Gold standard" measurement | Sensitivity (%) (95%CI) | Specificity % (95%CI) | Positive LR (95%CI) | Negative LR (95%CI) | p-Value | |
|---|---|---|---|---|---|---|---|
Clubbing (n = 60) | No Clubbing (n = 140) | ||||||
Nail bed fluctuation (n = 58) | 43 | 15 | 71.7 (59.2, 81.5) | 89.3 (83.1, 93.4%) | 6.7 (4.1, 11.1) | 0.3 (0.2, 0.5) | < 0.001 |
Increased nail curvature (n = 53) | 38 | 15 | 63.3 (50.7, 74.4%) | 89.3 (89.3, 93.4%) | 5.9 (3.5, 9.9) | 0.4 (0.3, 0.6) | < 0.001 |
Schamroth's sign (n = 41) | 30 | 11 | 50.0 (37.7, 62.3%) | 92.1 (86.5, 95.6%) | 6.4 (3.4, 11.8) | 0.5 (0.4, 0.7) | < 0.001 |
Definite clubbing (n = 37) | 31 | 06 | 51.7 (39.3, 63.8%) | 95.7 (91.0, 98.0%) | 12.1 (5.3, 27) | 0.5 (0.4, 0.7) | < 0.001 |
At least one sign (n = 76) | 47 | 29 | 78.3 (66.4, 86.9%) | 79.3 (71.8, 85.2%) | 3.8 (2.7, 5.4) | 0.3 (0.2, 0.4) | < 0.001 |
Two or more signs (n = 54) | 41 | 13 | 68.3 (55.8, 78.7%) | 90.7 (84.8, 94.5%) | 7.4 (4.3, 12.7) | 0.3 (0.2, 0.5) | < 0.001 |
No Clinical Sign (n = 123) | 13 | 110 | 21.7 (13.1, 33.6%) | 21.4 (15.4 – 28.9%) | 0.3 (0.2, 0.5) | < 0.001 | |
One Clinical Sign (n = 23) | 06 | 17 | 10.0 (4.9, 20.1%) | 87.9 (81.4, 92.3%) | 0.8 (0.3, 2.0) | 0.633 | |
Two Clinical Signs (n = 18) | 08 | 10 | 13.3 (6.9, 24.2%) | 92.9 (87.4, 96.1%) | 1.9 (0.8, 4.5) | 0.130 | |
Three Clinical Signs (n = 14) | 12 | 02 | 20.0 (11.8, 31.8%) | 98.6 (94.9, 99.6%) | 14.0 (3.2, 61) | < 0.001 | |
Four Clinical Signs (n = 22) | 21 | 01 | 35.0 (24.2, 47.6%) | 99.3 (96.1, 99.9%) | 49.0 (6.7, 356) | < 0.001 | |