Table 4. Spatial-temporal clusters analysis of HFMD in Qingdao City, 2013–2018.

Year	Cluster type	Cluster time	Radius(km)/towns(n)	Observed cases	Expected cases	RR	LLR	P-value
2013	Most-likely	Jun 1-Sep 30	18.97(47)	2478	1874.12	1.61	145.24	<0.001
	Secondary	May 1-Aug 31	12.53(4)	171	103.73	1.67	18.65	<0.001
2014	Most-likely	May 1-Oct 31	6.98(24)	1700	978.79	1.88	246.10	<0.001
	Secondary	May 1-Oct 31	0.00(1)	236	45.15	5.33	201.25	<0.001
2015	Most-likely	Jun 1-Aug 31	19.66(40)	4973	3323.46	1.87	529.81	<0.001
2016	Most-likely	Jun 1-Aug 31	25.03(53)	4222	2913.58	1.82	399.85	<0.001
2017	Most-likely	Jul 1- Aug 31	19.66(39)	3853	2285.85	2.09	607.18	<0.001
2018	Most-likely	Jul 1- Aug 31	22.92(49)	3844	2425.37	1.92	482.61	<0.001
	Secondary	Jun 1-Sep 30	10.41(2)	95	46.00	2.07	20.01	<0.001