Preliminary evidence for the development of a stroke specific geriatric depression scale.
Measuring depression among persons with stroke faces many challenges; diagnostic tools are lengthy and do not measure the extent of depression; screening tools are not stroke-specific; and metrics from the available indices do not provide a value that is mathematically or clinically meaningful.


OBJECTIVE
To provide evidence for the development of a stroke specific Geriatric Depression Scale screening measure (SS-GDS) through Rasch methodology.


METHODS
Secondary analyses of a randomized controlled trial post-stroke. Interviews from 91 subjects aged 71 (SD 10) over three time points or 240 interviews were analyzed. Rasch Analysis helped transform the 30-item GDS onto a logit scale. Unidimensionality, item fit, redundancy, and differential item functioning (DIF) were assessed.


RESULTS
Seventeen items fit the model to form a hierarchical measure ranging in difficulty from +1.2 to -1.8 logits. Preliminary psychometric properties of reliability, validity, and responsiveness were adequate. Two items that demonstrated DIF, one for language and one for gender, were split.


CONCLUSIONS
The 17-item SS-GDS Rasch measure was developed to screen for post-stroke depression (PSD) and provide an important step toward quantifying PSD. If revalidated in a larger sample, the SS-GDS could provide a mathematically valid index to screen for depression in stroke survivors.
Cinamon
Julie S
JS
Department of Psychology, Concordia University, Montreal, Quebec, Canada.
Finch
Lois
L
Miller
Sydney
S
Higgins
Joanne
J
Mayo
Nancy
N
D000368:Aged; D000369:Aged, 80 and over; D003866:Depressive Disorder / Q000175:diagnosis*; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000523:psychology*