THE IPCS COLLABORATIVE STUDY ON NEUROBEHAVIORAL SCREENING METHODS - IV - CONTROL DATA

The goal of the international Programme on Chemical Safety (IPCS) Coll aborative Study on Neurobehavioral Screening Methods was to determine the intra-and inter-laboratory reliability of a functional observation al battery (FOB) and an automated assessment of motor activity in eigh t laboratories worldwide. The control data were crucial to the outcome of the studies in terms of sensitivity and reliability of the lest me asures, which in turn impact on the between-laboratory comparisons of chemical effects. In addition, analyses of control data can aid in det ermining endpoints that may require modification to improve their sens itivity and reliability. The control data from the eight laboratories were examined in terms of the following parameters: 1) control variabi lity within studies for each laboratory; 2) within-laboratory replicab ility of control values across studies; 3) within-laboratory stability oi control values over the course of testing for a given study; and 4 ) between-laboratory comparisons of parameters (1), (2), and (3). The analyses indicated considerable differences across endpoints, wherein some measures showed high variability and little replicability, while others were extremely reproducible. Generally, there were similar rang es of variability and replicability of control data across laboratorie s, although in some cases one or two laboratories were markedly differ ent from the others. The physiological (weight, body temperature) and neuromuscular (grip strength, landing foot splay) endpoints exhibited the least variability, whereas the subjective assessments of reactivit y varied the most. These data indicate a reasonable degree of comparab ility in the data generated in the participating laboratories. (C) 199 7 Intox Press, Inc.