Table 2. Summary of absentees, signals, and outbreaks in each monitored school.

School	N of students	N of absentees	Average absentees per day	N of absentees for illness	Average absentees for illness per day	N of signals	N of suspected signals	N of true signals	Outbreaks	Diseases
1	88	10	0.03	7	0.02	0	0	0	0
2	99	27	0.08	17	0.05	0	0	0	0
3	163	31	0.09	14	0.04	2	0	0	0
4	182	35	0.10	22	0.07	0	0	0	0
5	201	7	0.02	6	0.02	0	0	0	0
6	223	129	0.38	86	0.26	4	1	0	0
7	242	1	0.01	1	0.00	0	0	0	0
8	243	55	0.16	51	0.15	5	1	0	0
9	267	19	0.06	13	0.04	0	0	0	0
10	277	37	0.11	20	0.06	0	0	0	0
11	290	134	0.40	114	0.34	5	2	0	0
12	309	5	0.01	4	0.01	0	0	0	0
13	414	56	0.17	44	0.13	1	0	0	0
14	1039	31	0.09	23	0.07	0	0	0	0
15	1108	49	0.15	48	0.14	6	4	0	0
16	1257	124	0.37	118	0.35	10	3	1	1	ILI
17	2212	952	2.82	768	2.28	21	9	3	2	varicella, mumps
Total	8614	1702	5.05	1356	4.02	52	20	4	3

There were 337 monitoring days during the whole period. Signals were generated by the EARS∼3Cs algorithm. Suspected signals were verified by data checking and spatial judgment. True signals were verified by epidemiologic investigation and clinical diagnosis.