. Author manuscript; available in PMC: 2012 Dec 1.

Published in final edited form as: Spat Spatiotemporal Epidemiol. 2011 Sep 29;2(4):291–300. doi: 10.1016/j.sste.2011.09.001

Table 1.

Approximate chi-square test applied with nominal significance levels to simulated data in circular study region

N = 400	α = 0.01 Type I Error (95%CI)	α = 0.05 Type I Error (95%CI)	α = 0.10 Type I Error (95%CI)

P(Disease)=0.01	0.034 (0.023,0.045)	0.151 (0.129,0.173)	0.269 (0.242,0.296)
P(Disease)=0.10	0.059 (0.044,0.074)	0.188 (0.164,0.212)	0.288 (0.260,0.316)
P(Disease)=0.50	0.062 (0.047,0.077)	0.179 (0.155,0.203)	0.272 (0.244,0.300)

N = 1,000	α = 0.01 Type I Error (95%CI)	α = 0.05 Type I Error (95%CI)	α = 0.10 Type I Error (95%CI)

P(Disease)=0.01	0.036 (0.024,0.048)	0.156 (0.134,0.178)	0.250 (0.223,0.277)
P(Disease)=0.10	0.048 (0.035,0.061)	0.156 (0.134,0.178)	0.256 (0.229,0.283)
P(Disease)=0.50	0.060 (0.045,0.075)	0.170 (0.147,0.193)	0.269 (0.242,0.296)

N = 1,600	α = 0.01 Type I Error (95%CI)	α = 0.05 Type I Error (95%CI)	α = 0.10 Type I Error (95%CI)

P(Disease)=0.01	0.045 (0.032,0.058)	0.181 (0.157,0.205)	0.283 (0.255,0.311)
P(Disease)=0.10	0.046 (0.033,0.059)	0.142 (0.120,0.164)	0.237 (0.211,0.263)
P(Disease)=0.50	0.047 (0.034,0.060)	0.156 (0.134,0.178)	0.235 (0.209,0.261)

N = 6,400	α = 0.01 Type I Error (95%CI)	α = 0.05 Type I Error (95%CI)	α = 0.10 Type I Error (95%CI)

P(Disease)=0.01	0.053 (0.039,0.067)	0.160 (0.137,0.183)	0.238 (0.212,0.264)
P(Disease)=0.10	0.044 (0.031,0.057)	0.147 (0.125,0.169)	0.237 (0.211,0.263)
P(Disease)=0.50	0.056 (0.042,0.070)	0.177 (0.153,0.201)	0.258 (0.231,0.285)