Number of patients with clinical features with streptococcal culture as reference standards in 306 patients with sore throat by streptococcal culture, southern Norway 2000–2002.
| GAS | C or G | Culture -ve | Total | GAS | C or G | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Clinical features | n= 127n (%) | n= 33n (%) | n= 146n (%) | n= 306n (%) | Sens | Spec | LR | Sens | Spec | LR |
| Centor criteria: | ||||||||||
| Cervical adenitis | 114 (90)a | 27 (82) | 101 (70) | 242 (80) | 0.90 | 0.30 | 1.3 | 0.82 | 0.30 | 1.2 |
| Absence of cough | 96 (76)a | 21 (64) | 67 (46) | 184 (60) | 0.76 | 0.54 | 1.7 | 0.64 | 0.54 | 1.3 |
| Reported fever >38.0°C | 67 (53) | 20 (61) | 69 (48) | 156 (52) | 0.53 | 0.52 | 1.1 | 0.61 | 0.52 | 1.3 |
| Tonsillar exudate | 32 (25) | 8 (24) | 48 (34) | 88 (29) | 0.25 | 0.66 | 0.8 | 0.24 | 0.66 | 0.8 |
| Considerable pain on swallowing | 70 (57)a | 12 (36) | 50 (35) | 132 (44) | 0.57 | 0.65 | 1.6 | 0.36 | 0.65 | 1.0 |
| Rubor in pharynx | 112 (88)a | 26 (79) | 106 (75) | 244 (81) | 0.88 | 0.25 | 1.2 | 0.79 | 0.25 | 1.1 |
| CRP value: | ||||||||||
| >25 mg/l | 68 (53) | 22 (67)a | 60 (41) | 150 (49) | 0.53 | 0.59 | 1.3 | 0.67 | 0.59 | 1.6 |
| >50 mg/l | 45 (35) | 11 (33) | 29 (20) | 85 (28) | 0.35 | 0.80 | 1.8 | 0.33 | 0.80 | 1.7 |
↵a P<0.05 in bivariate analysis of GAS versus group with no bacteria. GAS = group A streptococci. Sens = sensitivity. Spec = specificity. LR = likelihood ratio. CRP = C-reactive protein.