Hours of work and shiftwork.
D000222:Adaptation, Physiological; D002940:Circadian Rhythm; D006804:Ergonomics; D005767:Gastrointestinal Diseases / Q000453:epidemiology; D006801:Humans; D010559:Personnel Management; D010561:Personnel Staffing and Scheduling; D012893:Sleep Wake Disorders / Q000453:epidemiology; D012917:Social Adjustment