Table 4.
Logistic regression analysis of diagnostic value of clinical features and blood tests in the diagnosis of GAS and C or G streptococci in addition to the presence of Centor criteria in 306 patients with sore throat by streptococcal culture, southern Norway 2000-2002.
| GAS | C or G streptococci | All streptococci | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Clinical feature | OR | (95% CI) | P-value | OR | (95% CI) | P-value | OR | (95% CI) | P-value |
| Four Centor criteria | 2.6 | (0.7 to 10.6) | 0.17 | 3.0 | (0.3 to 31.7) | 0.36 | 2.3 | (0.6 to 8.5) | 0.23 |
| Three Centor criteria | 3.5 | (1.0 to 12.3) | 0.04 | 3.7 | (0.4 to 32.6) | 0.23 | 3.5 | (1.1 to 11.2) | 0.03 |
| Two Centor criteria | 3.0 | (0.9 to 10.1) | 0.07 | 3.2 | (0.4 to 27.2) | 0.29 | 2.8 | (0.9 to 8.4) | 0.07 |
| One Centor criterion | 1.9 | (0.5 to 7.0) | 0.34 | 3.5 | (0.4 to 31.7) | 0.26 | 2.0 | (0.6 to 6.5) | 0.26 |
| Zero Centor criteria (reference) | 1.0 | 1.0 | 1.0 | ||||||
| Rubor in pharynx | ns | ns | ns | ||||||
| Considerable pain on swallowing | 2.5 | (1.4 to 4.5) | 0.003 | ns | 1.8 | (1.0 to 3.1) | 0.04 | ||
| Mild/moderate pain (reference) | 1.0 | 1.0 | |||||||
| Duration of symptoms | |||||||||
| <4days | 2.0 | (1.1 to 3.5) | 0.02 | ns | 1.7 | (0.9 to 2.9) | 0.06 | ||
| ≥4 days (reference) | 1.0 | 1.0 | |||||||
| Age 3–14 years | 2.6 | (1.4 to 5.0) | 0.003 | ns | 2.1 | (1.1 to 3.9) | 0.02 | ||
| Other ages (reference) | 1.0 | 1.0 | |||||||
| CRP >25 mg/l | ns | 2.5 | (0.9 to 6.6) | 0.07 | 1.1 | (0.5 to 2.1) | 0.84 | ||
| CRP >50 mg/l | 2.8 | (1.0 to 7.5) | 0.04 | 2.0 | (1.0 to 3.8) | 0.04 | |||
| CRP <25 mg/l (reference) | 1.0 | 1.0 | |||||||
OR = Odds ratio. CRP = C-reactive protein. GAS = group A streptococci.