Table 2.

Longitudinal association between the severity of periodontitis and incidence of Parkinson’s disease.

Variables	n	Events	Person-years	Incidence rate per 1000 person-years	Model 1	Model 2	Model 3	Model 3 (3-year lag)	Model 3 (5-year lag)
Periodontitis
No	5,922,621	24,034	42,772,055.50	0.56191	1 (reference)	1 (reference)	1 (reference)	1 (reference)	(reference)
Yes	903,063	4,245	6,532,573.13	0.64982	1.099 (1.064, 1.136)	1.082 (1.047, 1.118)	1.090 (1.06,1.121)	1.103 (1.069,1.138)	1.109 (1.068,1.151)
Type of periodontitis
None	5,922,621	24,034	42,772,055.50	0.56191	1 (reference)	1 (reference)	1 (reference)	1 (reference)	1 (reference)
Mild	660,675	3,331	4,771,056.49	0.69817	1.103 (1.063, 1.143)	1.088 (1.049, 1.128)	1.095 (1.063,1.128)	1.102 (1.066,1.139)	1.101 (1.059,1.263)
Moderate	212,612	803	1,545,323.43	0.51963	1.095 (1.021, 1.175)	1.069 (0.997, 1.148)	1.076 (1.005,1.153)	1.127 (1.045,1.215)	1.156 (1.059,1.263)
Severe	29,776	111	216,193.21	0.51343	1.026 (0.852, 1.237)	0.999 (0.829, 1.204)	0.987 (0.82,1.188)	0.999 (0.813,1.228)	1.088 (0.86,1.377)
Visit one year after treatment of periodontitis
No periodontitis	5,922,621	24,034	42,772,055.50	0.56191	1 (reference)	1 (reference)	1 (reference)	1 (reference)	1 (reference)
No re-visit	844,743	3,938	6,109,817.15	0.64454	1.094 (1.058, 1.132)	1.078 (1.042, 1.115)	1.078 (1.04,1.119)	1.099 (1.055,1.144)	1.119 (1.067,1.174)
Re-visit	58,320	307	422,755.98	0.72619	1.165 (1.041, 1.304)	1.136 (1.015, 1.272)	1.114 (1.062,1.146)	1.108 (1.062,1.157)	1.097 (1.042,1.154)

Model 1 was adjusted for age and sex.

Model 2 was adjusted for the values in Model 1 plus smoking status, drinking habits, exercise habits, income level, body mass index, diabetes mellitus, hypertension, and dyslipidemia.

Model 3 was adjusted for the values in Model 2 plus stroke and depression.