Reliability and validity of a rating scale for post-stroke psychiatric symptoms

Reliability and validity of a rating scale for post-stroke psychiatric symp toms were examined by the videotape method. The scale comprised 10 items ca tegorized into two symptom domains of decreased spontaneity and impaired em otion. Also, two items for global assessment of the two symptom domains wer e added. Each item had seven anchor points from 0, representing no impairme nt, to 6, corresponding to complete impairment. Face validity of the scale was confirmed through the questionnaire sun;ey. Nine neurologists independe ntly assessed psychiatric symptoms in 30 videotaped post-stroke patients. W eighted kappa coefficients of more than 0.5 were noted for all the items ex cept for one item. Data from three cerebral metabolism enhancers trials wer e used to examine the validity. Changes in severity in the Global Change Sc ale (GCS) from the baseline to the final assessment was assessed by raters' impression in these trials. Factorial validity of the scale was confirmed by the factor analysis. GCS in the three trials were considerably related t o the summed scores of the items in the two categories. Namely, in the box plot figures, boxes of the middle 50% of data well differentiated the adjac ent categories of GCS. However, overlap from vertical bars was observed. Th ese results suggest reliability and validity of the scale.