School-based surveillance of acute infectious disease in children: a systematic review

BMC Infectious Diseases

Table 2 Outbreak definitions used within included studies

First Author & year of publication	Outbreak threshold / alert	Time period of breach
Chu 2013 [52]	Exceedance based on C2-MEDIUM method^a OR > 5% all-cause absenteeism^b	Single day Single day
Kom Mogto 2012 [49]	≥10% ILI-related absenteeism	Single day
Lenaway 1995 [45]	> 7.5% illness absence	Single week average
Mann 2011 [41]	≥8% all-cause absenteeism AND 1 SD above 30 day mean	Single day
Suzue 2012^c [50]	> 2% ILI-related absenteeism	Single day
Williams 2013 [42]	> 10% all-cause absenteeism > 5% ILI-related absenteeism	2 or more consecutive school days

^a C2-MEDIUM method calculates the mean and standard deviation (SD) from −9 to −3 days before the day of interest. Threshold is an exceedance of the expected value by three standard deviations
^b Not clearly stated, assumed from description of methods
^c Threshold used to detect start and end of pandemic

ISSN: 1471-2334