Potential causal effect of physical activity on reducing the risk of dementia: a 6-year cohort study from the Japan Gerontological Evaluation Study

Table 1 Characteristics of the participants (N = 73,260)

	Non-snowy area (n = 55,188)		Snowy area (n = 18,072)		Standardized differences^a
	n	%	n	%	Standardized differences^a
Men	25,924	47.0	8107	44.9	−0.05
Age, years (mean [SD])	73.7	0.03	74.4	0.05	0.13
Education					−0.09
Low	22,327	40.5	8175	45.2
Middle	20,549	37.2	6411	35.5
High	11,121	20.2	3044	16.8
Missing or other	1191	2.2	442	2.4
Household income					−0.17
Low	22,572	40.9	8413	46.6
Middle	17,332	31.4	4905	27.1
High	4851	8.8	1132	6.3
Missing	10,433	18.9	3622	20.0
Married	39,257	71.1	12,405	68.6	−0.05
Missing	1325	2.4	574	3.2
Engaging in paid work	11,939	21.6	3646	20.2	−0.04
Missing	5324	9.6	1738	9.6
Cardiometabolic diseases
Heart disease	5653	10.2	2106	11.7	0.03
Stroke	1657	3.0	647	3.6	0.04
Diabetes	7069	12.8	2354	13.0	0.02
Missing	3768	6.8	1023	5.7
Depressive symptoms					0.09
Not depressed	34,218	62.0	10,539	58.3
Moderately depressed	8564	15.5	3309	18.3
Severely depressed	2849	5.2	1052	5.8
Missing	9557	17.3	3172	17.6
Drinker	19,049	34.5	6531	36.1	0.02
Missing	910	1.6	263	1.5
Smoker	5536	10.0	1787	9.9	0.00
Missing	979	1.8	320	1.8
Exchanging support with family	45,128	81.8	14,627	80.9	−0.02
Missing	656	1.2	205	1.1
Having contact with friends	38,167	69.2	12,478	69.0	− 0.02
Missing	2976	5.4	895	5.0
Participating in community groups	37,686	68.3	12,834	71.0	0.03
Missing	5462	9.9	1487	8.2
The frequency of physical activity per week, times (mean [SD])	1.38	0.01	1.25	0.01	−0.11
Missing	9806	17.8	3159	17.5
Dementia incidence	6218	11.3	2496	13.8	0.09

^aIn general, standardized differences less than 0.1 indicate balance between the two groups

ISSN: 1479-5868