Performance of WHO clinical decision rule for streptococcal pharyngitis in three countries
| Country | GABHS + n (%) (95% CI) | WHO CDR+ n (%) (95% CI) | Sensitivity (95% CI) | Specificity (95% CI) | PPV (95% CI) | NPV (95% CI) | |||
|---|---|---|---|---|---|---|---|---|---|
| *Statistically significant difference between sites, p⩽0.05. | |||||||||
| Age 2–12 years | |||||||||
| Brazil (n = 191) | 47 (24.6) (18.7 to 31.4) | 10 (5.2) (2.5 to 9.4) | 8.5 (2.4 to 20.4) | 95.8 (91.2 to 98.5) | 45.5 (12.2 to 73.8) | 76.7 (69.4 to 82.2) | |||
| Croatia (n = 200) | 84 (42.0) (35.1 to 49.2) | 12 (6.0) (3.1 to 10.2) | 5.9 (1.9 to 13.4) | 93.9 (93.9 to 87.9) | 41.7 (15.2 to 72.3) | 57.9 (50.6 to 65.1) | |||
| Egypt (n = 1419) | 387 (27.7) (24.9 to 29.7) | 47 (3.3) (2.4 to 4.4) | 4.1 (2.4 to 6.6) | 97.0 (95.7 to 97.9) | 34.0 (20.9 to 49.3) | 72.9 (70.5 to 75.3) | |||
| p value (χ2 by site) | ⩽0.001 | ⩽0.001 | 0.363 | 0.202 | 0.855 | ⩽0.001 | |||
| Age <5 years | |||||||||
| Brazil (n = 81) | 10 (12.4) (6.1 to 21.5) | 3 (3.7) (0.8 to 10.4) | 0.0 (0.0 to 30.9) | 95.7 (88.1 to 99.1) | 0.0 (0.0 to 70.7) | 87.2 (77.7 to 93.7) | |||
| Croatia (n = 64) | 28 (43.8) (31.4 to 56.7) | 3 (4.7) (0.98 to 13.1) | 3.6 (0.1 to 18.4) | 94.4 (81.3 to 99.3) | 33.3 (0.8 to 90.6) | 55.7 (42.5 to 68.5) | |||
| Egypt (n = 749) | 175 (23.7) (20.4 to 26.6) | 27 (3.6) (2.4 to 5.2) | 4.6 (1.9 to 8.8) | 96.7 (94.9 to 98.0) | 29.6 (13.8 to 50.2) | 76.9 (73.6 to 79.9) | |||
| p value (χ2 by sites) | ⩽0.001 | ⩽0.001 | 0.770 | 0.735 | 0.534 | ⩽0.001 | |||
| Age 5–12 years | |||||||||
| Brazil (n = 110) | 37 (33.6) (24.9 to 43.3) | 7 (6.3) (2.6 to 12.7) | 10.8 (3.0 to 25.4) | 95.9 (88.5 to 99.1) | 57.1 (18.4 to 90.1) | 67.9 (58.0 to 76.8) | |||
| Croatia (n = 136) | 56 (41.8) (32.8 to 49.9) | 9 (6.6) (3.1 to 12.2) | 7.1 (1.9 to 17.3) | 93.8 (86.0 to 97.9) | 44.4 (13.7 to 78.8) | 59.1 (49.9 to 67.7) | |||
| Egypt (n = 670) | 212 (31.6) (28.1 to 35.3) | 20 (2.9) (1.8 to 4.6) | 3.8 (1.6 to 7.3) | 97.4 (95.5 to 98.6) | 40.0 (19.1 to 63.9) | 68.6 (64.9 to 72.2) | |||
| p value (χ2 by site) | 0.099 | 0.099 | 0.162 | 0.221 | 0.734 | 0.109 | |||