Table 3.

Summary of the fitted parameters of the multivariate ARIMAX model analysis in Guangzhou, 2001–2016

Model	Fitted		Test RMSE	Risk factors
	AIC	RMSE		Vars	Coef.	s.e.	T	P-value
ARIMAX(0,1,1)(0,0,2)12 with ICs and Tmin	393.7854	0.7520	0.6445
				ma1	0.3472	0.0714	4.8636	<0.0001**
				sma1	0.3631	0.0842	4.3105	<0.0001**
				sma2	0.1730	0.0745	2.3207	0.0215*
				ICs (lag0)	0.0047	0.0017	2.7640	0.0064**
				Tmin (lag0)	0.0347	0.0170	2.0484	0.0421*

ARIMAX, autoregressive integrated moving average with external regressors; Fitted, fitted results; Test, test results; AIC, Akaike Information Criterion; RMSE, root mean square error; Coef., coefficient of risk factors; lag, time lag of risk factors; s.e., standard error; t, t statistic; ma1, MA(1); sma1, seasonal MA(1); sma2, seasonal MA(2).

**P < 0.01, *P < 0.05.