0138 Discrepancy Between Subjective and Objective Measures of Habitual Sleep in Veterans with Gulf War Illness

Abstract Introduction Even though there is variability in symptom presentation, fatigue and sleep disturbance are commonly reported by veterans with Gulf War Illness (GWI), with deployed veterans reporting greater symptom burden. Discrepancies have been found between self-report and objective measures of sleep in clinical populations, however, this has yet to be examined in veterans with GWI. This analysis examined the associations between sleep discrepancy and self-reported measures of health in veterans with GWI. Methods In a sample of 85 veterans with GWI (Mage=54.2±7.1y, 87.1% male), objective sleep was assessed over a seven-day period using wrist-worn actigraphy and subjective habitual sleep was assessed using the Pittsburgh Sleep Quality Index (PSQI). Actigraphy data were manually scored and averaged across the seven nights to derive habitual measures of objective sleep parameters that are available on the PSQI: total sleep time (TST), sleep onset latency (SOL), and sleep efficiency (SE). Global sleep discrepancy was calculated as an index for TST ([objective TST – subjective TST]/ objective TST) and difference scores for SOL and SE (objective – subjective). Participants completed a series of questionnaires to assess symptoms of depression, posttraumatic stress disorder (PTSD), and GWI as well as fatigue, pain, cognitive difficulties, and stress. Correlation analysis was conducted to examine associations between measures of global sleep discrepancy and self-reported measures of health. Results The majority of the participants underestimated SOL (55.3%) and overestimated SE (68.8%) on the PSQI relative to actigraphy. Correlation analyses revealed that global sleep discrepancy in TST was associated with fatigue and GWI gastrointestinal symptoms (p< 0.05). For SOL, global sleep discrepancy was associated with fatigue, stress, cognitive difficulties, hyperarousal PTSD symptoms, and GWI symptoms (p< 0.05). No associations were observed for global sleep discrepancy in SE. Conclusion Discrepancies between subjective and objective measures of habitual sleep were observed in veterans with GWI, and were found to be associated with several self-reported measures of health, thus emphasizing the importance of measuring the multidimensionality of sleep. Additional research is needed to investigate the implications of sleep discrepancy among veterans with GWI. Support (if any) Veterans Affairs, Office of Research and Development, Clinical Science Research and Development under Merit Review Grant #SPLD-013-13S.