Psychometric properties of the DASS-Depression scale among a Brazilian population with chronic pain.
BACKGROUND
Depression is a common contributor to suffering and disability in people with chronic pain. However, the assessment of depression in this population has been hampered by the presence of a number of somatic symptoms that are shared between chronic pain, treatment side-effects and traditional concepts of depression. As a result, the use of depression measures that do not contain somatic items has been encouraged.


OBJECTIVE
This study examined the psychometric properties of the Depression sub-scale of the Depression Anxiety and Stress Scales (DASS) in a Brazilian chronic pain patient population.


METHODS
Data on a number of measures were collected from 348 participants attending pain facilities.


RESULTS
Principal components and exploratory factor analyses indicated the presence of only one factor. Item analyses indicated adequate item-scale correlations. The Cronbach alpha was .96, which suggests an excellent internal consistency.


CONCLUSIONS
The DASS-Depression scale has adequate psychometric properties and its further use with Brazilian chronic pain populations can now be supported.
D000328:Adult; D000368:Aged; D001938:Brazil; D002908:Chronic Disease; D003431:Cross-Cultural Comparison; D003866:Depressive Disorder / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000523:psychology*; D010555:Personality Inventory / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000706:statistics & numerical data; D011602:Psychophysiologic Disorders / Q000523:psychology*; D015203:Reproducibility of Results; D012803:Sick Role