Table 1.

The Centor score

Symptoms	Points	Score	Post-test probability
Tonsillar exudates	1	0	2.5%
Tender anterior cervical adenopathy	1	1	6.5%
Absence of cough	1	2	15.4%
History of fever (> 38.0°C)	1	3	31.6%
		4	55.7%

Patients receive a point for the presence or absence of signs and symptoms. Each patient is assigned a score between 0 and 4 which is associated with a post-test probability as calculated by Centor and colleagues [16]. (The post-test probability values presented are the mean of the original probability intervals reported by Centor and colleagues.)