Table 1.

Internal consistency of CES-D scale

Item	N	Item-test correlation	Item-rest correlation	Average interitem correlation	Alpha
Bothered	14927	0.6711	0.5651	0.2962	0.7911	0.7911
Mind	14927	0.6255	0.5098	0.3039	0.7971	0.7974
Depress	14927	0.7375	0.6478	0.2849	0.7819	0.7815
Effort	14927	0.6845	0.5817	0.2939	0.7893	0.789
Hopeful	14927	0.4442	0.2993	0.3348	0.8191	0.819
Fearful	14927	0.566	0.439	0.314	0.8047	0.8046
Sleep_rest~s	14927	0.5263	0.3927	0.3208	0.8096	0.8103
Happy	14927	0.6103	0.4915	0.3065	0.7991	0.7996
Lonely	14927	0.6245	0.5085	0.3041	0.7973	0.7973
Get_going	14927	0.6377	0.5245	0.3018	0.7955	0.7954
Test scale				0.3061	0.8152	0.8152

Source: CHARLS national baseline data