Table 3.

Factors related to temporal correction factors for indoor radon concentration using GEE method.

Parameter	Beta	SE	p value
(Intercept)	0.153	0.231	0.51
Montha
[month = 1]	0.129	0.269	0.63
[month = 2]	0.079	0.234	0.74
[month = 3]	0.220	0.255	0.39
[month = 4]	0.309	0.318	0.33
[month = 5]b	0
[month = 6]	− 0.604	0.606	0.32
[month = 7]	− 0.604	0.438	0.17
[month = 8]	− 0.837	0.502	0.10
[month = 9]	− 0.239	0.320	0.45
[month = 10]	0.151	0.233	0.52
[month = 11]	− 0.129	0.288	0.65
[month = 12]	0.117	0.266	0.66
rCO2	1.029	0.235	< 0.001
Month × rCO2
[month = 1] × rCO2	− 0.521	0.296	0.08
[month = 2] × rCO2	− 0.470	0.248	0.06
[month = 3] × rCO2	− 0.476	0.261	0.07
[month = 4] × rCO2	− 0.414	0.334	0.22
[month = 5] × rCO2	0
[month = 6] × rCO2	1.539	0.476	< 0.001
[month = 7] × rCO2	1.249	0.345	< 0.001
[month = 8] × rCO2	1.326	0.379	< 0.001
[month = 9] × rCO2	0.249	0.296	0.40
[month = 10] × rCO2	− 0.509	0.239	0.03
[month = 11] × rCO2	− 0.174	0.305	0.57
[month = 12] × rCO2	− 0.572	0.278	0.04

Dependent variable: Radon temporal correction factors.

^aThe reference category was month = 5.

^bThis parameter is set to zero because it is redundant.