Table 4

Relative risk of suicide associated with the level of air pollen counts, stratified by age group

Pollen counts	≤35 years old		36–60 years old		>60 years old		Difference by age†
Pollen counts	RR‡	95% CI	RR‡	95% CI	RR‡	95% CI	Difference by age†
Total
0	1		1		1		χ²=6.6092 df=8.0246 p=0.5819
<10	1.028	0.917 to 1.152	1.037	0.963 to 1.117	1.039	0.949 to 1.136
10–<30	1.143*	1.011 to 1.292	1.057	0.973 to 1.148	1.059	0.958 to 1.170
30–100	1.106*	1.001 to 1.222	1.103**	1.033 to 1.177	1.200**	1.112 to 1.296
>100	1.026	0.907 to 1.162	1.091*	1.007 to 1.181	1.082	0.983 to 1.192
Males
0	1		1		1		χ²=7.3468 df=8.0017 p=0.4999
<10	1.133	0.996 to 1.288	1.068	0.974 to 1.171	1.076	0.958 to 1.208
10–<30	1.168*	1.013 to 1.346	1.076	0.971 to 1.192	0.983	0.859 to 1.125
30–100	1.057	0.940 to 1.189	1.105*	1.019 to 1.199	1.149**	1.037 to 1.273
>100	1.099	0.953 to 1.267	1.142**	1.035 to 1.260	1.066	0.938 to 1.212
Females
0	1		1		1		χ²=13.3307 df=8.4450 p=0.1207
<10	0.738	0.575 to 0.946	0.976	0.861 to 1.106	0.979	0.850 to 1.128
10–<30	1.062	0.832 to 1.355	1.012	0.881 to 1.163	1.150	0.990 to 1.335
30–100	1.239**	1.029 to 1.491	1.088	0.977 to 1.212	1.254**	1.116 to 1.409
>100	0.860	0.667 to 1.109	1.005	0.879 to 1.150	1.094	0.945 to 1.267

*p<0.05; **p<0.01.
†The p value represents the reduction down to a model estimating the effect of levels of pollen counts adjusted for region, age groups, calendar time, temperature, cloud cover and humidity in the total participants, the men and the women, respectively.
‡Estimates of relative risk were derived from the model adjusted for region, calendar time, temperature, cloud cover and humidity.
RR, relative risk.