Table 2.

The correlation coefficients of temporal risk indices of pertussis infections and internet query in Shandong province by city, 2009–2017

City	Time-series	Peaking number	Increasing intensity	CTRM
Dezhou	0.68**	0.85*	0.80*	1.06
Heze	0.62**	0.69*	0.62**	0.77
Jinan	0.78*	0.85*	0.80*	1.13
Jining	0.68**	0.79*	0.68*	0.91
Laiwu	0.52**	0.55**	0.52**	0.59
Liaocheng	0.72*	0.81*	0.77*	1.02
Taian	0.77*	0.87*	0.83*	1.18
Zaozhuang	0.53**	0.57*	0.53**	0.61
Zibo	0.80*	0.85*	0.80*	1.15
Dongying	0.58**	0.64*	0.58**	0.66
Weihai	0.78*	0.81*	0.78*	1.07
Linyi	0.71*	0.78*	0.71*	0.94
Qingdao	0.81*	0.85*	0.81*	1.17
Binzhou	0.72*	0.79*	0.72*	0.96
Rizhao	0.52**	0.57**	0.52**	0.60
Yantai	0.83*	0.87*	0.83*	1.24
Weifang	0.63*	0.67*	0.63**	0.76

**: P < 0.01, *: P < 0.05.