title: The impact of shift work on Brazilian train drivers with different chronotypes: a comparative analysis through objective and subjective criteria.
abstract: OBJECTIVE
  The aim of this study was to compare sleep pattern, tiredness sensation and quality of life between different chronotypes in train drivers from a Brazilian transportation company.
  
  
  METHODS
  Ninety-one train drivers, working a rotary work schedule including night shift, were divided into three groups according to their chronotype (morning types, intermediate or evening types) and were assessed for their sleep and quality of life, as characterized by a subjective questionnaire and the Psychomotor Vigilance Task (PVT), applied before and immediately after the night shift. The pattern of activity and rest was measured for 10 days by actigraphy, and the chronotype was determined through the Morningness-Eveningness Questionnaire.
  
  
  RESULTS
  Forty-one (45.1%) individuals were classified as morning type, 44 (48.4%) were classified as intermediate and 6 (6.6%) as evening type. The evening types had a tendency to remain awake for a longer period of time before the night shift (p = 0.05) and scored worse overall for quality of life compared to morning types (p = 0.11). There was no significant difference between the groups regarding variability in the PVT performance, even when covaried by the period of waking time before the test. There was no significant difference either in feelings of fatigue before and after starting the shift.
  
  
  CONCLUSIONS
  Although the evening type number was small, evening type individuals scored worse relative to sleep and quality of life than morning type individuals.
authors: Centro de Estudo Multidisciplinar em Sonolência e Acidentes (CEMSA), Universidade Federal de São Paulo, São Paulo, Brazil.
authors: Silvio
authors: S
authors: de Araújo Fernandes
authors: Leandro
authors: L
authors: Stetner Antonietti
authors: Amanda
authors: A
authors: Saba
authors: Alexandre
authors: A
authors: Paulino de Faria
authors: Andrea
authors: A
authors: Maculano Esteves
authors: Sergio
authors: S
authors: Tufik
authors: Marco
authors: M
authors: Túlio de Mello
mesh_terms: D056044:Actigraphy; D000328:Adult; D001938:Brazil; D005221:Fatigue / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009790:Occupations; D010561:Personnel Staffing and Scheduling; D017286:Polysomnography; D011788:Quality of Life; D020178:Sleep Disorders, Circadian Rhythm / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014851:Wakefulness; D055815:Young Adult