Fatigue assessment in the field: validation of a hand-held electronic psychomotor vigilance task.

INTRODUCTION In recent years, there has been an increasing need for a reliable and practical tool for assessing fatigue-related impairment in the field. This study investigated the sensitivity of one potential tool, a 5-min version of the psychomotor vigilance task (PVT) specifically designed for use on personal digital assistants (PDA), to 28 h of sustained wakefulness. METHODS There were 15 participants who slept in the laboratory overnight then remained awake from 08:00 (Day 1) to 12:00 (Day 2). During every second hour, they completed a 10-min PVT, a sustained attention task that is sensitive to the effects of sleep loss and fatigue, and a 5-min PDA-PVT. RESULTS While performance on both tasks significantly varied as a function of hours of wakefulness, responses on the PDA-PVT were typically slower than on the PVT. When performance scores were standardized, the negative impact of increasing hours of wakefulness on performance on the 5-min PDA-PVT and 10-min PVT did not significantly differ. DISCUSSION The findings suggest that the 5-min PDA-PVT may provide a reasonable substitute for the 10-min PVT, particularly in circumstances where a shorter test is required and/or the standard PVT is not as practical.