Table 3.

multivariable negative binomial regression analysis results between year, season, sex, and age group with incidence of leptospirosis

Variables	IRR	95% CI	P value
Year of occurrence
2010	Ref	_	_
2011	0.543	(0.281,1.026)	0.061
2012	0.25	(0.106,0.536)	0.001
2013	0.337	(0.157,0.684)	0.003
2014	0.73	(0.402,1.314)	0.294
2015	1.033	(0.597,1.796)	0.907
2016	0.956	(0.546,1.677)	0.874
2017	0.53	(0.282,0.98)	0.046
2018	0.748	(0.418,1.334)	0.323
2019	0.466	0.244,0.872	0.019
Season of the year
Winter	Ref	_	_
Spring	1.166	(0.765,1.782)	0.475
Summer	1.184	(0.778,1.808)	0.431
Fall/autumn	1.422	0.947,2.147	0.091
Sex
Female	Ref	_	_
Male	2.239	(1.664,3.034)	<0.001
Age group
≤17	Ref	_	_
18-44	8.045	(4.654,15.147)	<0.001
≥45	7.391	(4.167,14.169)	<0.001

IRR: incidence rate ratio; CI: confidence interval; ref: reference category; MNBR: multivariable negative binomial regression