Table 2.

Comparison of mean difference of incidence rates by clusters using the post hoc test (Bonferroni as multiple comparisons).

Cluster	Comparison cluster	Mean difference	Significance	95% confidence interval
				Lower bound	Upper bound
High risk	Moderate risk	3215.37∗	<0.001	2165.4269	4265.3065
	Low risk	6117.46∗	<0.001	5143.6194	7091.3006
	Very low risk	−5927.09∗	<0.001	−7628.1869	−4225.9931
Moderate risk	Low risk	2902.09∗	<0.001	2271.8722	3532.3145
	Very low risk	−9142.46∗	<0.001	−10672.9938	−7611.9195
Low risk	Very low risk	−12044.55∗	<0.001	−13523.9201	−10565.1799

^∗Mean difference is significant at p < 0.001.