Table 1.

Results of the spatial scan analysis of pancreatic cancer mortality at the county level in Shandong for the years 2011 to 2013.

Cluster	County amount	Cases	Expected	Annual case/100000	RR	LLR	P value
Total without adjusted for age
Most likely cluster*	52	5769	3637	6.3	2.18	850.27	<0.01
Secondary cluster 1	1	128	56	9.1	2.28	33.47	<0.01
Secondary cluster 2	16	1480	1259	4.7	1.20	20.74	<0.01
Secondary cluster 3	1	161	111	5.8	1.46	10.08	<0.01
Total adjusted for age
Most likely cluster	78	2815	2146	2.0	1.90	211.69	<0.01
Secondary cluster 1	1	54	21	3.8	2.57	17.89	<0.01
Urban Without adjusted for age
Most likely cluster	23	1791	982	9.1	2.31	358.99	<0.01
Secondary cluster 1	1	61	25	12.3	2.49	18.97	<0.01
Secondary cluster 2	1	38	13	14.2	2.86	15.11	<0.01
Secondary cluster 3	1	80	44	9.1	1.84	12.10	<0.01
Urban adjusted for age
Most likely cluster	23	624	383	3.2	1.94	83.92	<0.01
Secondary cluster 1	2	79	42	3.6	1.91	13.10	<0.01
Rural without adjusted for age
Most likely cluster	65	4488	3150	5.0	2.32	549.81	<0.01
Rural adjusted for age
Most likely cluster	65	1547	1151	1.7	1.95	131.13	<0.01

Note *: “Most likely cluster” was defined when the maximum log likelihood ratio (LLR) with statistical significance was detected by Monte Carlo simulation in spatial analysis; the other LLR values with statistical significance were identified as “Secondary cluster”. The relative risk (RR) was the ratio of the mortality inside a cluster area to the mortality outside a cluster area.