TABLE 3.

Effect of radical cure of Helicobacter pylori on Parkinson’s disease (PD).

Country	References	Study	Method of Hp detection	Hp (+) in the PD patients group	Hp (+) in the control group	OR(95%CI)
United Kingdom	Charlett et al., 1999	Case-control	ElISA	23/33	31/78	3.49(1. 46, 8.32)
United Kingdom	Dobbs et al., 2000b	Case-control	ElISA	25/58	43/136	1.64 (0.87, 3.09)
Krean	Lee et al., 2008	nRCT	13C-urea breath test	35/65	–	–
United Kingdom	Charlett et al., 2009	Cross-sectional	ElISA	57/120	77/196	1.40 (0.88, 2.21)
Denmark	Nielsen et al., 2012	Case-control	Prescriptions for Hp eradication drugs	138/4484	505/22416	1.38(1.14, 1.67)
United Kingdom	Blaecher et al., 2013	Case-control	RT-PCR	17/60	42/256	2.01 (1.05, 3.87)
Malaysia	Nafisah et al., 2013	Cross-sectional	13C-urea breath test	14/29	5/23	3.36 (0.98, 11.49)
China	Bu et al., 2015	Case-control	ElISA	60/131	44/141	1.86 (1.14, 3.06)
Malaysia	Tan et al., 2015	Case- cohort	13C-urea breath test	33/102	–	–
Greece	Tsolaki et al., 2015	Case-control	Gastroscopy and histologic examination	6/9	14/31	2.43 (0.51, 11.51)
India	Mridula et al., 2017	Prospective case cohort	ElISA	18/36	–	–
Greece	Efthymiou et al., 2017	Case-control	ElISA	14/39	33/68	0.59 (0.26, 1.33)