Emergency Medical Services (EMS) commonly schedules providers to work shifts of 24-hours or longer, con- tributing to severe fatigue, occupational injury, and potentially putting patients at risk. Our long-term goal is to identify shift schedules that are safe for providers and the patients they treat and transport. These schedules must consider the frequency of emergency responses on an average shift, feasibility and utilization of on-shift rest, and also conform to workforce availability and cost constraints. The overall objective of this application is to determine the extent to which scheduling, health behaviors, and workplace factors increase risk of negative safety outcomes. The central theme is that individual and agency- specific factors compound the risk of negative safety outcomes posed by extended shifts. We hypothesize that untreated sleep disorders, adverse health behaviors, and frequent calls for emergency response that reduce sleep opportunity increase the risk for motor vehicle crashes and occupational injuries. Completion of this work will identify modifiable factors amenable to intervention and assist in design of agency-level scheduling strate- gies and interventions to improve safety. The application proposes three specific aims. Aim 1: Test the hypothesis that a greater number of emergency responses per shift will be associated with less on-shift sleep. Our preliminary data suggest on-shift sleep var- ies and may be related to the opportunity for rest. Aim 2: Test the hypothesis that individual factors, such as sleep disorders and simultaneous employment at multiple jobs, increase the risk of injury, motor vehicle crash- es (MVCs), and near-miss MVCs. Our preliminary data suggest that EMS providers with sleep disorders (e.g., obstructive sleep apnea, shift work disorder, insomnia) and those who work multiple jobs will have an in- creased risk of negative safety outcomes. Aim 3: Test the hypothesis that EMS agency-level factors, such as policies that restrict daytime sleep and policies that allow more than 24 hours of consecutive work, increase the risk of injury, MVCs, and near-miss MVCs. Preliminary data suggest that these policies are common and may increase the risk of negative safety outcomes through fatigue-related performance decrements. The outcomes of this proposal will characterize the relative importance of individual-level and agency-level fac- tors with respect to occupational safety. The proposed analysis will determine the extent to which sleep is ob- tained across settings with varying environmental conditions and demands. These findings are critical for de- termining appropriate policies for shift-length regulation among EMS clinicians who must provide emergency services 24-hours per day. We will identify the rate of crashes on the commute home from work, an unexplored area of risk in this workforce.