Table 3.

Count time-series regression of monthly arthropod-related mortality in Iran (2016–2023)

Term	Estimate	SE	IRR	IRR (lower 95% CI)	IRR (upper 95% CI)	p
(Intercept)	1.1545	0.1091	3.1723	2.5618	3.9283	<0.001
t	0.0010	0.0018	1.0010	0.9976	1.0045	0.558
s1	0.6794	0.0844	1.9727	1.6718	2.3278	<0.001
c1	-0.8596	0.0954	0.4233	0.3511	0.5104	<0.001
s2	0.2097	0.0796	1.2334	1.0552	1.4416	0.008
c2	-0.2002	0.0785	0.8186	0.7019	0.9546	0.011

T linear time term, s1/c1 and s2/c2 annual and semi-annual Fourier terms, IRR incidence rate ratio