Use of the psychomotor vigilance test to aid in the selection of risk controls in an air medical transport operation.

Study objectives: This study evaluated the utility and ecological validity of the 3-minute psychomotor vigilance test (PVT) completed by safety-critical personnel in an air medical transport operation as part of a fatigue risk management program.

Methods: Crewmembers in an air medical transport operation self-administered an alertness assessment incorporating a 3-minute PVT at different time points during their duty schedule. The prevalence of alertness deficits was evaluated based on a failure threshold of 12 errors considering both lapses and false starts. To evaluate the ecological validity of the PVT, the relative frequency of failed assessments was evaluated relative to crewmember position, timing of the assessment within the duty schedule, time of day, and sleep quantity in the last 24 h.

Results: 2.1% of assessments were associated with a failing PVT score. Crewmember position, timing of assessment within the duty shift, time of day, and sleep quantity in the last 24 h were found to affect the relative frequency of failed assessments. Obtaining less than 7-9 h of sleep was associated with systematic increases in the failure rate (F[1, 54 612] = 168.1, p < .001). Obtaining less than 4 h of sleep was associated with a frequency of a failed assessment 2.99 times higher than the frequency of a failed assessment when obtaining 7-9 h of sleep.

Conclusions: Results provide evidence for the utility and ecological validity of the PVT as well as the suitability of the PVT failure threshold to support fatigue risk management in safety-critical operations.