Measuring the severity of depression through a self-report inventory. A comparison of logistic, factorial and implicit models.
The present study investigates the psychometric adequacy of a self-report inventory of depression (the QD2) with respect to the severity of depressive symptoms, within the framework of a unidimensional model of depressive states. Responses to the 52 QD2 items, by 481 subjects divided into four groups (depressed, psychiatric, somatic and control), were subjected to a Rasch analysis. Results show that 15 items (QSD(R1] display a satisfactory goodness of fit for both items and persons, as defined by the Rasch model. This set of items, solely related to 'pure' depression, gives a measure of the severity of depression, free from anxiety symptoms. The discussion focuses upon the advantages of the Rasch model as compared to traditional tests. The Rasch 15-item solution should provide a parsimonious tool for future studies on the classification of depressive disorders.
de Bonis
M
M
CNRS, Paris, France.
Lebeaux
M O
MO
de Boeck
P
P
Simon
M
M
Pichot
P
P
D000328:Adult; D001714:Bipolar Disorder / Q000145:classification / Q000175:diagnosis* / Q000523:psychology; D003866:Depressive Disorder / Q000145:classification / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D015233:Models, Statistical; D010555:Personality Inventory / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000379:methods