Table 2: Descriptive statistics and Cronbach's alpha coefficients of dependent and independen variables ( 𝑁 = 7 2 8 ).

VariablesMeanSDItemsRangeThe Cronbach’s alpha

GHQ-12(1)29.77 5.56 1217–480.84
GHQ-12(2)4.66 2.20 120–110.48
Effort(3)13.69 4.74 66–300.87
Rewards(3)39.92 8.29 1111–550.91
Overcommitment(3)13.60 3.48 66–240.80
Depressive(4)1.42 0.17 211.00–1.860.69
Cyclothymic(4)1.30 0.22 211.00–2.000.85
Hyperthymic(4)1.27 0.18 211.00–1.860.78
Irritable(4)1.18 0.18 211.00–1.860.85
Anxious(4)1.24 0.21 261.00–1.960.89

(1)Scored using the Likert method (1-2-3-4).
(2)Scored using the GHQ method (0-0-1-1).
(3)Subscales of the Japanese short version of Effort-Reward Imbalance scale.
(4)Affective temperaments assessed by the TEMPS-A.