Table 1 Mokken scaling of the Chinese Cardiac Depression Scale with items showing invariant item ordering (n = 438)

There is only misery in the future for me

2.52

0.40

The possibility of sudden death worries me

2.75

0.37

I feel frustrated

2.85

0.45

I am not the person I used to be

2.89

0.41

I feel like I'm living on borrowed time

2.97

0.35

I may not recover completely

3.13

0.37

I feel independent and in control of my life

3.15

0.30

I gain just as much pleasure from my leisure activities as I used to*

3.21

0.35

I get hardly anything done

3.32

0.37

I get pleasure from life at present*

3.43

0.38

I feel good in spirits*

3.52

0.35

I wake up in the early hours of the morning and cannot get back to sleep

3.67

0.32

I can't be bothered doing anything much

3.78

0.31

My problems are not over yet

3.79

0.35

My memory is as good as it always was*

3.85

0.32