Self- and observer assessment in anxiolytic drug trials: a comparison of their validity.
Self-rating scales are considered to be less useful for comparing different treatments in anxiety patients than observer-rating scales. However, the empirical evidence for this assumption is not adequate. A self-rating inventory of 35 items related to anxiety was perfectly parallel with an observer-rating inventory. Both instruments were used in the Cross National Collaborative Panic Study to compare the efficacy of imipramine, alprazolam and placebo in an 8-week drug trial in a sample of 1168 outpatients. The variance of the self-rating assessments was about two times higher. Both scales were equally sensitive to change; however, the measurement of change by means of the self-rating scale was slightly less consistent. The discriminative power of the observer-rating scale between placebo and active treatment was two to three times higher than that of the self-rating scale; consequently the observer-rating procedure provides a more valid instrument when the efficacies of different anxiolytic treatments are compared between different groups of patients.
Maier
W
W
Department of Psychiatry, University of Mainz, Federal Republic of Germany.
Albus
M
M
Buller
R
R
Nutzinger
D
D
Shera
D
D
Bech
P
P
D000328:Adult; D000525:Alprazolam / Q000627:therapeutic use*; D001008:Anxiety Disorders / Q000188:drug therapy*; D004311:Double-Blind Method; D006801:Humans; D007099:Imipramine / Q000627:therapeutic use*; D008875:Middle Aged; D010200:Panic / Q000187:drug effects; D010552:Personality Assessment / Q000706:statistics & numerical data*; D010556:Personality Tests / Q000706:statistics & numerical data*; D011594:Psychometrics; D015203:Reproducibility of Results
D007099:Imipramine; D000525:Alprazolam