PSYCHOMOTOR VIGILANCE TEST PERFORMANCE DECLINES RELATED TO ILLNESS SEVERITY, NOT SLEEP

Abstract Introduction While the Psychomotor Vigilance Test (PVT) has been used extensively to track vigilance degradation following sleep loss, there is evidence that it may also track vigilance degradation related to illness. However, it is unclear how much performance decline is driven by sleep loss related to an illness or the illness itself independent of sleep loss. Here we assessed how sleep and acute infectious diarrhea impact vigilance performance in a controlled human infection model (CHIM) with enterotoxigenic Escherichia coli (ETEC). Methods During a CHIM assessing the efficacy of an immunoprophylactic targeting ETEC, we measured sleep via actigraphy over an 8-day inpatient period. A 10-minute PVT was also administered up to three times each day in the morning, afternoon, and evening. Participants ingested an oral immunoprophylaxis 3 times/day on days -2 and -1, and ingested ETEC on day 0. Participants were categorized as to whether or not they experienced the primary endpoint of moderate-severe diarrhea (MSD). Results Among 56 participants (aged 34.7±8.5 years, 64% male), 54% reached the primary endpoint of moderate-severe diarrhea following ETEC infection. Total sleep times across the study did not differ between those with and without MSD. While PVT minor lapses (i.e., not responding within 500 milliseconds) did increase following ETEC infection for all subjects as revealed by a mixed linear model [effect of day: f(7,657)=3.35, p=0.002], there was also a significant main effect of group [f(1,657)=5.85, p=0.016], where those participants who experienced MSD following ETEC infection had more minor lapses across the study than those who did not experience MSD (6.28±0.43 vs 4.88±0.38). Conclusion While the negative impact of sleep loss on performance has been well demonstrated, these are the first data to suggest that illness severity[KT1] , independent of sleep loss, also negatively impacts performance. In operational populations such as the military, special care should be taken to prevent illness and remove ill operators from the field, just as this care should be taken to prevent sleep loss and remove sleepy operators. By preventing and monitoring sleep loss and illness, these operations can avoid potentially costly performance errors. Support (If Any) The clinical trial from which these data were obtained was funded by the Congressionally Directed Medical Research Program through the Joint Warfighter Medical Research Program under Award No. W81XWH-15-C-0083 to the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. The U.S. Army Medical Research Acquisition Activity was the awarding and administering acquisition office. The study was also funded by a Collaborative Research and Development Agreement with PATH Enteric Vaccine Solutions (NCRADA-NMRC-15-9589), as well as by the Military Operational Medicine Research Program (MOMRP).