Use of rasch methodology to develop a short version of the Health Related Quality of life for Eating Disorders questionnaire: a prospective study

Table 2 Rasch model: Item measure, SE, fit statistics and item-total correlations of the mental health and functionality domain

		Mental health and functionality
Item ^a	Content	δ	SE	Infit	Outfit	r _t
(7) PR48	Do you have to stop performing some tasks as a result of your physical problem?	1.16	0.06	1.04	1.05	0.67
(6) PR47	Do you find it difficult to maintain attention as a result of your physical problem?	0.80	0.06	1.11	1.03	0.71
(4) ER41	Do you have to make an extra effort or invest more time than usual as a result of your emotional problems?	0.27	0.06	0.86	0.81	0.76
(5) ER42	Do you accomplish less than you would like to as a result of your emotional problem?	0.17	0.06	0.90	0.85	0.77
(2) MH37	Do you have very sudden mood changes that you find difficult to control?	0.06	0.06	1.17	1.20	0.62
(3) MH40	Do you feel worthless?	-0.35	0.06	0.73	0.73	0.80
(10) PT51	Do you set very high goals and feel dissatisfied if you do not meet them?	-0.39	0.06	1.17	1.14	0.68
(9) PT50	Do you think that you have to do things perfectly or just not to do them at all?	-0.42	0.06	1.24	1.24	0.68
(8) PT49	Do you feel lack of confidence in your own capabilities?	-0.45	0.06	0.87	0.88	0.73
(1) MH36	Do you feel happy?	-0.86	0.06	0.84	0.95	0.64

Every question has a response scale of 6 ordinal options, being 0 = Never and 5 = Always.
δ = Level of severity of the social maladjustment factor. Higher values indicate higher severity; SE = standard error;r _t = correlation between item and total measured social maladjustment level based on the Rasch calibrated item scores and total scores.
^aThe numbers in parentheses reflect the current item location in the shortened version.
This English translation has not been validated linguistically. We provide an approximate translation of the Spanish items into English.

ISSN: 1477-7525