A clinical trial demonstration of a web-based test for alcohol and drug effects.

OBJECTIVE: The purpose of this study was to determine the feasibility of a Web-installed test of skills essential to driving: target detection and divided attention. The Attention Assessment (TAA) was designed for use in global clinical trials to document the effects of alcohol and other drugs. METHOD: Scoring algorithms and data-storage tools were installed on servers in bicoastal U.S. locations. IBM PC-compatible test units with encrypted Web access and 19-inch monitors were installed at a Canadian site. A single-center, crossover design was used to compare the pharmacodynamic properties of a pharmaceutical compound under development with those of alcohol (blood alcohol concentration [BAC]=.10%) over time. For this study, 33 subjects completed four 36-hour testing periods. Blood samples and pharmacodynamic assessments were performed at 0, 1, 3, 5, 7, 9, 12, and 24 hours. Analysis of covariance was conducted on six composite TAA scores as change from baseline. RESULTS: Five of the six composite scores showed significant ethanol effects (p<.02) over a BAC range of. 1% to .05%. Within-session test-retest reliability was r=.86 and between periods was r=.51 (between Periods 1 and 2), .83 (between Periods 2 and 3), and .81 (between Periods 3 and 4). Individual impairment was evident at .05%. CONCLUSIONS: It was possible to conduct sensitive alcohol/other drug testing from a central database with secure scoring. Test installation, data monitoring, and norms assembly were performed at a remote location. TAA gives researchers the ability to immediately and normatively evaluate alcohol and drug effects in diverse global locations. Secondary applications include clinical or worksite testing. The data show improved precision over previous test versions to map the effect of drugs on visual/cognitive skills involved in driving.

Relative influences of adjunctive topiramate and adjunctive lamotrigine on scanning and the effective field of view.

A subsample of 67 adult patients with partial seizures participating in a randomized, double-blind study comparing the cognitive effects of adjunctive lamotrigine (LTG) and adjunctive topiramate (TPM) was administered Performance On-Line (POL) in addition to a battery of neuropsychological tests at baseline, week 8 and week 16 of treatment. The POL is a self-administered computer task that measures scanning, divided-attention, and the effective field of view. Although the POL does not measure driving performance, POL scores are correlated with driving performance. The results show that adjunctive TPM, but not adjunctive LTG, negatively impacted cognition. Both simple target identification and divided-attention performance on POL were compromised in the TPM group but not in the LTG group. The relative POL impairment associated with chronic TPM treatment was similar to that observed with the acute effects of alcohol with a breath level of .045% or a low dose of alprazolam (0.5mg). Thus, driving-related visual and cognitive skills were compromised by adjunctive TPM treatment. Therapeutic doses of adjunctive TPM pose a potential risk of impaired scanning and divided-attention skills.