Table 1 Characteristics of WOFC members and control groups before propensity score matching

Age (years), mean (SD)

72.4 (5.5)

74.8 (6.2)

Education, n (%)

 ≥ 13 years

1,343 (44.3)

26,866 (29.6)

 10‒12 years

1,431 (47.3)

42,756 (47.0)

 ≤ 9 years

255 (8.4)

21,230 (23.4)

Household income (ten thousand yen), mean (SD)

313.3 (177.3)

229.2 (157.9)

Marital status (Married), n (%)

2,035 (67.1)

56,847 (62.5)

Living alone, n (%)

555 (18.3)

17,250 (18.9)

Frequency of participation in income-generating activities, n (%)

 None

1,572 (51.9)

50,322 (55.4)

 Once a week or less

180 (6.0)

6,399 (7.0)

 Two or three times a week,

322 (10.6)

9,855 (10.9)

 Four or more times a week

955 (31.5)

24,276 (26.7)

Population density, n (%)

 Metropolitan (≥ 4000 people/km2)

2,073 (68.5)

26,291 (29.6)

 Urban (1000–3999 people/km2),

833 (27.5)

26,270 (28.9)

 Rural (< 1000 people/km2)

123 (4.0)

37,651 (41.4)

Self-reported illness, n (%)

 Hypertension

1,142 (37.7)

40,420 (44.4)

 Stroke

40 (1.3)

1,242 (1.3)

 Heart diseases

127 (4.1)

5,525 (6.0)

 Diabetes mellitus

253 (8.3)

9,672 (10.6)

 Musculoskeletal disorders

545 (17.9)

12,963 (14.2)

 Cancer

82 (2.7)

2,796 (3.8)

Frequency of going out (Less than once a week), n (%)

54 (1.7)

6,279 (6.9)

Daily walking time (≥ 60 min), n (%)

1,274 (42.0)

33,175 (36.5)

Social participation (More than once a month), n (%)

 Sports group

1,290 (42.5)

24,863 (27.3)

 Hobby group

1,498 (49.4)

26,213 (28.8)