Table 1: Demographic variables N=145.
Due to missing values, the total number does not represent the total percentage for some items.
a: Fisher's exact test, b: Wilcoxon rank sum test
Indices Items Double-income nuclear family Single-mother P-value
n=131 n=14
Mean
n
SD
%
Mean
n
SD
%
Age rangea 20s 17 12.98 5 35.71 0.0637
30s 87 66.41 5 35.71
40s 26 19.85 4 28.57
50s 1 0.76 0 0
Type of householda Parents and their children (double income) 131 100 0 0 <0.0001
Mother and children 0 0 10 71.43
Grandparents, mother, and children 0 0 4 28.57
Mother's employment statusa Full-time worker 83 66.94 5 35.71 0.1213
Dispatched employee 3 2.42 1 7.14
Part-time worker 34 27.42 8 57.14
Executive officer 1 0.81 0 0
Self-employed business 1 0.81 0 0
Others 2 1.61 0 0
Work hours/dayb (Mean, SD) 8.21 1.59 8.58 1.04 0.5748
Working on weekendsa 71 54.20 10 71.43 0.2661
Working at nighta 7 5.34 0 0 1
Monthly disposable income (Yen)b ≥100,000 to <150,000 1 0.79 2 14.29 <0.0001
≥150,000 to <200,000 6 4.76 6 42.86
≥200,000 to <250,000 7 5.56 0 0
≥250,000 to <300,000 7 5.56 4 28.57
≥300,000 to <350,000 21 16.67 0 0
≥350,000 to <400,000 21 16.67 0 0
≥400,000 63 50 2 14.29