Table 2 Subgroup characteristics of those with impaired cognitive function in the 2016 and 2019 surveys

n/mean

%/SD

n/mean

%/SD

p^a

n/mean

%/SD

n/mean

%/SD

p^a

Age in years

79.5

(5.5)

80.0

(5.6)

0.52

83.4

(7.2)

82.7

(6.0)

0.34

Married

62

(71.3%)

77

(65.8%)

0.45

35

(37.2%)

58

(32.2%)

0.42

Living alone

21

(24.4%)

36

(29.8%)

0.43

34

(35.8%)

96

(52.2%)

0.011

Years of residence

25.8

(16.6)

29.3

(17.6)

0.16

22.7

(15.4)

25.1

(15.6)

0.23

Being employed

5

(5.8%)

15

(12.2%)

0.15

0

(0.0%)

3

(1.6%)

0.55

Household income ≥3 million yen

9

(13.4%)

20

(18.9%)

0.41

4

(5.5%)

14

(9.1%)

0.44

Not depressed (5-item GDS < 2)

14

(20.0%)

23

(21.9%)

0.85

12

(15.2%)

49

(28.7%)

0.026

Number of comorbidities, none

4

(4.5%)

2

(1.7%)

0.030

8

(8.3%)

5

(2.6%)

0.14

 1 comorbidity

15

(17.0%)

16

(13.2%)

16

(16.7%)

37

(19.4%)

 2 comorbidities

14

(15.9%)

33

(27.3%)

25

(26.0%)

38

(19.9%)

 3 comorbidities

27

(30.7%)

20

(16.5%)

13

(13.5%)

30

(15.7%)

 ≥4 comorbidities

28

(31.8%)

50

(41.3%)

34

(35.4%)

81

(42.4%)

Number of impaired IADL items, none

4

(4.5%)

14

(11.2%)

< 0.001

7

(7.2%)

14

(7.3%)

< 0.001

 1 item impaired

18

(20.5%)

13

(10.4%)

27

(27.8%)

19

(9.9%)

 2 items impaired

64

(72.7%)

30

(24.0%)

61

(62.9%)

38

(19.8%)

 3-5 items impaired

2

(2.3%)

68

(54.4%)

2

(2.1%)

121

(63.0%)