Table 2. Item characteristics, item-total correlations, α if item deleted of the Kessler psychological distress scale (K10) (n = 2548).

K10 item	Mean	SD	Median	IQR	Corrected item-total correlation	α if item deleted
Fatigue	0.66	0.79	0	1	0.52	0.84
Nervous	0.55	0.71	0	1	0.58	0.83
So nervous	0.13	0.44	0	0	0.58	0.84
Hopeless	0.33	0.65	0	0	0.59	0.83
Restless/fidgety	0.31	0.61	0	0	0.60	0.83
So restless	0.11	0.41	0	0	0.58	0.84
Depressed	0.55	0.76	0	1	0.58	0.83
So depressed	0.15	0.47	0	0	0.61	0.83
Lack of energy	0.44	0.76	0	1	0.47	0.84
Worthless	0.21	0.53	0	0	0.58	0.83
Global K10 score a	3.42	4.10	2.0	4	–	0.85

Note: Data from eight participants were missing for the K10. SD = standard deviation; IQR = interquartile range.

^aOverall Cronbach’s alpha.