. Author manuscript; available in PMC: 2014 Dec 15.

Published in final edited form as: Psychiatry Res. 2013 Aug 22;210(2):10.1016/j.psychres.2013.07.015. doi: 10.1016/j.psychres.2013.07.015

Table 7.

Item fit statistics and misfit order for the four category of the PHQ-9 questionnaire using the Rasch Analysis

PHQ-9 item	Measure	Fit statistics
PHQ-9 item	Measure	Infit mean square	Outfit mean square
Low energy	-0.83	0.98	1.04
Anhedonia	-0.37	0.93	1.03
Depressed mood	-0.34	0.81	0.74
Feelings of worthlessness or guilt	-0.04	0.83	0.71
Appetite disturbances	-0.02	1.17	1.23
Sleep disturbances	0.06	1.29	1.26
Trouble concentrating	0.18	1.23	1.15
Psychomotor agitation/retardation	0.65	1.15	0.96
Suicidal thoughts	0.72	1.04	0.78