Validity of the aphasia item from the Scandinavian Stroke Scale.
We studied the validity of the aphasia item of a widely used stroke scale - the Scandinavian Stroke Scale (SSS) - in discriminating between aphasia and normal language function in 33 stroke patients of an acute stroke unit. They were assessed by a nurse using the aphasia item from the SSS and by a speech and language therapist carrying out a full evaluation of the language function. The latter served as the 'gold standard'. The agreement between the nurses' and the speech and language therapist's scoring was good (weighted kappa = 0.74, 95% CI 0.51-0.97), and the sensitivity and specificity of the SSS aphasia item were also satisfactory. However, the predictive value of a positive test was as low as 0.55 (95% CI 0.23-0.83), indicating nearly every second of the positives being false positive. Using the aphasia score of the SSS as a diagnostic aid for aphasia after stroke results in a high rate of false positives and inflates the prevalence figures for aphasia in epidemiological studies of stroke.
Thommessen
Bente
B
Department of Geriatric Medicine, Ullevaal Hospital, Oslo, Norway. bente.thommessen@ioks.uio.no
Thoresen
Gerd Eva
GE
Bautz-Holter
Erik
E
Laake
Knut
K
D000368:Aged; D000369:Aged, 80 and over; D001037:Aphasia / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009730:Nursing Assessment; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012537:Scandinavian and Nordic Countries / Q000453:epidemiology; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index