TEST-RETEST RELIABILITY AND INFLUENCE OF PRACTICE EFFECTS ON PERFORMANCE IN A MULTIUSER COMPUTERIZED PSYCHOMETRIC TEST SYSTEM FOR USE IN CLINICAL PHARMACOLOGICAL STUDIES

Fifty naive drug-free healthy young male or female volunteers performe d psychometric tests an 6 sessions with 3- to 4-days intervals, using a new multi-user computerized test system for use in clinical pharmaco logy. Tests of simple reaction time, complex reaction time, concentrat ion, motor coordination, and shortterm memory (word pairs or figures) were performed. Clear practice effects were shown for almost every psy chometric variable recorded. The magnitude differed considerably betwe en tests. The magnitude of practice effects was most evident (46.5-55. 0 %) for the concentration test, the coordination test, and the Vienna reaction test. Intermediate practice effects (20.8-31.0 %) were obser ved with the complex reaction test (percent correct reactions) and bot h short-term memory tests (test duration). Only small practice effects (5.1-14.3 %) were observed with the reaction times of the simple and the complex reaction test, and the percent correct responses in the sh ort-term memory tests. After 3 test sessions, significant further impr ovements could not be shown for most tests, but for the reaction times in the simple and the complex reaction test this was true from the fi rst or the second test session, respectively. For the concentration te st and the coordination test, significant practice effects could be sh own even after 5 training sessions. It is recommended to perform at le ast one training session before the start of clinical pharmacological studies with psychometric testing. Test-retest-reliability, as determi ned from session 5 to session 6 by Spearman's rank correlation coeffic ient (R-S), was very good (greater than or equal to 0.95) for the conc entration test (percent correct responses) and the coordination test ( mean steering time). Most other variables showed intermediate (0.44-0. 68) reliability (reaction times in the simple and complex reaction tes t, percent correct reactions in the complex reaction test, percent err ors in the concentration test, test duration of the short-term memory tests). The percent correct answers, which is the primary variable in both short-term memory tests, had a relatively poor reliability (0.14- 0.18).