0313 Implementation Outcomes from a Multi-Component Lighting Intervention in Shiftworkers on a High-Security Submarine Watchfloor

Abstract

Abstract Introduction Shiftwork is prevalent in the military and causes circadian health and performance impairments. Negative consequences may be mitigated through evidence-based lighting solutions that optimize timing, spectrum and intensity of exposure; however, the practical utility of these solutions hinges on their implementation and adoption. Therefore, we examined the implementation effectiveness of a multi-component lighting intervention that had demonstrated efficacy for improving alertness and performance in active duty service members working nightshift schedules on a high-security watchfloor. Methods Participants worked 12-h shifts (0530-1730) (N=56, 9 females; mean+SE age=28.95 + 0.76). Lighting interventions included two types of LED panels (3,721 cm2) that were either enhanced (SW+) or depleted (SW-) in short wavelength energy (both ~3000 K, ~300 lux at 46 cm from eyes). For both SW+ and SW- conditions, a bank of panels were arranged across the front of the watchfloor and illuminated the entire nightshift. In addition, blue-blocker glasses were worn after nightshifts up until bedtime, and eye masks were worn during sleep for both intervention conditions. Data collection coincided with existing watchfloor schedules: there was an 8-day baseline (BL1) and 8-day SW+ condition, and an 8-day baseline (BL2) and 8-day SW- condition (order within those 16-day periods was pseudo-randomized). Implementation was measured via weekly questionnaires. Results Participants who completed BL1, SW+, and SW- conditions (n =24) reported more positive feelings (happy, alert, relaxed) and fewer negative feelings (sad, sleepy, anxious) with both interventions compared to standard lights (BL1) (p< 0.05 for both SW+ and SW-). More negative symptoms (e.g. glare, headache, fatigue) were reported in BL1 versus the intervention conditions (p< 0.01). Most participants reported that alertness was the same or better under intervention conditions (96% SW+, 95% SW-); 75% found both the blue-blocker glasses and eye masks somewhat or very easy to use; and 100% reported sleep as either the same or better with each intervention tool. Finally, most participants reported they would want to keep the intervention lights at the end of the study. Conclusion The intervention was generally well-received by participants, thus providing evidence for the feasibility of implementing multi-component lighting strategies to mitigate the negative consequences of shiftwork. Support (if any) ONR TS-788