Table 2.

Main results

Method	CHARLS		SHARE
	Coefficient	P	Coefficient	P
Fixed effects regression (Model 1)	0.0003	0.0290	0.0022	< 0.0001
Fixed effects regression (Model 2)	0.0003	0.0380	0.0019	< 0.0001
Fixed effects regression (Rural)	0.0004	0.0250	0.0031	< 0.0001
Fixed effects regression (Urban)	0.0001	0.6220	0.0016	0.0005
Fixed effects regression (≥ 65 years old)	0.0003	0.3140	0.0025	< 0.0001
MR	= 1.2933, 95%CI: 1.2045–1.3820, P < 0.0001

Note: Model 1 is not adjusted. Model 2 adjusted for age, marital status, education, smoking status, drinking status, retirement status, BMI, mean annual NO₂ concentration and temperature. OR: Odds ratio; CHARLS: the China Health and Retirement Longitudinal Study; SHARE: the Survey of Health, Aging and Retirement in Europe; MR: Mendelian randomization