Premium
Rasch analysis of the hospital anxiety and depression scale in Parkinson's disease
Author(s) -
Forjaz Maria João,
RodriguezBlázquez Carmen,
MartinezMartin Pablo
Publication year - 2009
Publication title -
movement disorders
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.352
H-Index - 198
eISSN - 1531-8257
pISSN - 0885-3185
DOI - 10.1002/mds.22409
Subject(s) - hospital anxiety and depression scale , rasch model , psychology , parkinson's disease , anxiety , differential item functioning , mood , depression (economics) , clinical psychology , psychometrics , psychiatry , disease , medicine , item response theory , developmental psychology , economics , macroeconomics
The hospital anxiety and depression scale (HADS) is commonly used to assess mood in Parkinson's disease (PD) patients. Very few studies analyze the scale from the standpoint of item response theory. This article sought to analyze how the HADS fits the Rasch model in PD. The HADS was administered to 387 PD patients. Three sets of Rasch analyses were performed for the HADS total score, and anxiety and depression subscales (HADS‐T, ‐A, and ‐D, respectively). Although the HADS‐T and HADS‐A displayed a good fit, with little threshold disordering and no differential item functioning, the HADS‐D failed to fit the model. The person separation index, a reliability measure, was 0.87 (HADS‐T) and 0.80 (HADS‐A). Both HADS‐T and HADS‐A showed unidimensionality. Our results supported the use of HADS‐T as a measure of psychological distress in PD patients. Moreover, the HADS‐A was also an adequate anxiety measure. Further research is required to address the use of HADS‐D in PD. © 2008 Movement Disorder Society