Neurobehavioral tests as a medical surveillance procedure: applying evaluative criteria

Neurobehavioral impairment is among the earliest indicators of a toxic insult on the nervous system. Neurobehavioral tests measure behavior impairment by noninvasive procedures that assess various performance and personality changes. Neurobehavioral tests have been used on groups of workers included in epidemiologic research studies; however, their suitability for an ongoing medical surveillance program for workers exposed to neurotoxic agents has not been evaluated. In Ontario, Canada, a set of validity criteria must be met to determine whether a medical procedure may be prescribed for a specific medical surveillance program. The evaluative criteria are standards for judging the desirability of a procedure based on social values and scientific considerations. In this paper, various studies using neurobehavioral tests are reviewed, and the validity of using these procedures for medical surveillance is evaluated by applying the Ontario evaluation criteria. The conclusion is that neurobehavioral tests are useful for well-controlled, cross-sectional studies, but they do not yet meet the validity criteria for procedures prescribed in an ongoing medical surveillance program for workers exposed to neurotoxic agents.