title: The effect of sleep disorder on the work ability of workers in a car accessories manufacturing plant.
abstract: BACKGROUND
  Work ability assessment and its affecting factors are important in the field of occupational health. One of the factors affecting work ability is sleep disorder, which is very common among workers. Therefore, the present study aimed to assess work ability and its relationship with sleep disorder in workers of a manufacturing plant.
  
  
  METHODS
  This cross- sectional study was conducted in a manufacturing plant in Tehran in 2013. All the 931 male workers of this plant were enrolled in the study, and their work ability was assessed using the Work Ability Index (WAI). The scores of this index range from 7 to 49, and the higher work ability score indicates a better work ability status. In this study, sleep disorder was assessed using the MUSIC-Norrtalje Questionnaire.
  
  
  RESULTS
  The average score of WAI was 42.81, ranging from 22 to 49. This score was significantly lower in the group with sleep disorder (41.28) than in the group without sleep disorder (44.10) (p< 0.001). The results of the logistic regression analysis revealed a significant relationship between work ability and sleep disorder even after adjustment for the confounding variables (OR= 2.52, 95% CI= 1.07 - 5.93, p= 0.033).
  
  
  CONCLUSIONS
  The results of this study found a relationship between sleep disorder and work ability. Therefore, it is recommended to identify workers with sleep disorder and attend to their problem in order to increase their work ability.
authors: 1. Associate Professor of Occupational Medicine, Occupational Medicine Department and Occupational Medicine Research Center, Iran University of Medical Sciences, Tehran, Iran. ylabbafinejad@yahoo.com.
authors: Yasser
authors: Y
authors: Labbafinejad
authors: 2. Assistant Professor of Occupational Medicine, Brain and Spinal Injury Research Center (BASIR), Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. m_ghafaari@yahoo.com.
authors: Mostafa
authors: M
authors: Ghaffari
authors: 3. Occupational Medicine Resident, Occupational Medicine Department, Iran University of Medical Sciences, Tehran, Iran. bahadori_baharak@yahoo.com.
authors: Baharak
authors: B
authors: Bahadori
authors: 4. Associate Professor of Occupational Medicine, Occupational Medicine Department, Iran University of Medical Sciences and Brain and Spinal Injury Research Center (BASIR), Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. sabermohammadi@gmail.com.
authors: Saber
authors: S
authors: Mohammadi
authors: 5. General Practitioner, Brain and Spinal Injury Research Center (BASIR), Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. persia_ab@yahoo.com.
authors: Alireza
authors: A
authors: Abdi
authors: 6. General Practitioner, Occupational Medicine Department, Iran University of Medical Sciences, Tehran, Iran. mohamad.namvar@gmail.com.
authors: Mohamad
authors: M
authors: Namvar
authors: 7. Associate Professor of Occupational Medicine, Occupational Medicine Department, Iran University of Medical Sciences and Brain and Spinal Injury Research Center (BASIR), Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. msattarchi@yahoo.com.
authors: Mirsaeed
authors: M
authors: Attarchi
keywords: Sleep disorder; Work Ability; Worker