Portuguese version of the Delirium Rating Scale-Revised-98: reliability and validity.
OBJECTIVE
To assess the validity and the reliability of the Portuguese version of the Delirium Rating Scale-Revised-98 (DRS-R-98).


METHODS
The scale was translated into Portuguese and back-translated into English. After assessing its face validity, five diagnostic groups (n=64; delirium, depression, dementia, schizophrenia and others) were evaluated by two independent researchers blinded to the diagnosis. Diagnosis and severity of delirium as measured by the DRS-R-98 were compared to clinical diagnosis, Mini-Mental State Exam, Confusion Assessment Method, and Clinical Global Impressions scale (CGI).


RESULTS
Mean and median DRS-R-98 total scores significantly distinguished delirium from the other groups (p<0.001). Inter-rater reliability (ICC between 0.9 and 1) and internal consistency (alpha=0.91) were very high. DRS-R-98 severity scores correlated highly with the CGI. Mean DRS-R-98 severity scores during delirium differed significantly (p<0.01) from the post-treatment values. The area under the curve established by ROC analysis was 0.99 and using the cut-off value of 20 the scale showed sensitivity and specificity of 92.6% and 94.6%, respectively.


CONCLUSIONS
The Portuguese version of the DRS-R-98 is a valid and reliable measure of delirium that distinguishes delirium from other disorders and is sensitive to change in delirium severity, which may be of great value for longitudinal studies.
de Negreiros
Daniel Philippi
DP
Post-Graduate Program in Medical Sciences, Federal University of Santa Catarina. danielnegreiros@yahoo.com
da Silva Meleiro
Alexandrina Maria Augusto
AM
Furlanetto
Letícia M
LM
Trzepacz
Paula T
PT
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003693:Delirium / Q000175:diagnosis*; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011174:Portugal; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D015203:Reproducibility of Results; D012720:Severity of Illness Index