Individuals most at risk for neurobehavioral performance impairment during sleep deprivation can be accurately identified by a single 10-minute baseline visual psychomotor vigilance task (vPVT), according to a study published in Scientific Reports.
Researchers compiled data from 151 healthy participants aged 18 to 30 years participating in an inpatient study of circadian rhythms with the Intensive Physiological Monitoring unit at Brigham & Women’s Hospital. Participants were kept awake in bed for 20 hours in a semi-recumbent posture under dim light. Researchers examined the predictive value of a neurobehavioral performance assessment under rested baseline conditions (evaluated at 8 hours awake following 8 hours of sleep) on neurobehavioral response to moderate sleep loss (evaluated at 20 hours awake two days later).
The response-to-sleep-loss phenotype was based on the number of attentional failures on the 10-min vPVT taken at 20 hours awake. A participant with fewer than 6 attentional failures (20th percentile) was defined as resilient, a participant with greater than 30 attentional failures (60th percentile) was defined as vulnerable, and a participant with between 6 and 30 attentional failures was defined as intermediate.
At 8 hours awake two days prior to the constant routine, 73 participants (48%) were found to have 2 or more attentional failures on vPVT, 32 (44%) of whom were found to be intermediate, 39 (53%) were found to be vulnerable, and 2 (3%) were found to be resilient at 20 hours awake two days later after two more nights of 8 hour sleep. All participants with 3 or more attentional failures on the vPVT at 8 h awake (n=57) were found to be non-resilient (n=19, 33% intermediate; n=38, 67% vulnerable) two days later at 20 hours awake.
The negative predictive value for a resilient response type was 97% for ≥2 attentional failures and 100% for ≥3 attentional failures on vPVT. Researchers identified 2 different levels of performance ability: high vs poor performance when rested and level of performance impairment (resilient, intermediate, or vulnerable phenotype).
Factors which may have limited these findings include the use of young and healthy individuals studied under highly controlled inpatient laboratory conditions. Further, the study design restricted the use of factors that known to affect neurobehavioral performance, such as caffeine and bright lights, which may affect the generalizability of these results. Researchers also note that the number of individuals categorized as intermediate or vulnerable at 20 hours of wakefulness may have been overestimated.
Despite these limitations, researchers believe these findings are likely to be highly reproducible under a range of real-world settings. They emphasized that “the screening tool developed in this study could have a significant impact on the health and safety of not only individuals in safety-sensitive occupations, who are either required to or decide to stay awake past the recommended 16-17 hours per day, but also on the general public who depend on those individuals to be operating at sufficient levels of performance across and beyond their work shifts.”
St. Hilaire MA, Kristal BS, Rahman SA, et al. Using a single daytime performance test to identify most individuals at high-risk for performance impairment during extended wake [published online November 13, 2019]. Sci Rep. doi: 10.1038/s41598-019-52930-y