Het.onderzoek objectives are: • the organization of a national survey in three business sectors with two instruments. The vow / QFT and WAI o 3 business sectors: construction, industrial cleaning (. Offices industrial workshops ...) and tertiary (mainly office work) o for each sector should be a random sample representative of the sector is possible to make 600 to interrogate employees, or 1,800 for the three sectors o the questionnaire VOW / QFT and Viagra should be used to interrogate the employees o ideally, questionnaires are not only completed by the employee, but he is best interviewed by a specialized person as an occupational physician. a psychologist • ... o ideally sampled both workers subject to health surveillance as employees who are not subject to its • contains the analysis of data collected o globally for all of the sectors describing the results. Statistical analyzes of the sleutelthematieken: age, gender, professional status ... oh by business sector but also comparisons between sectors • comparing the results obtained with the VOW / QFT and those obtained with the WAI and the conclusion on the possible complementarities these two questionnaires • update the standards of the VOW / QFT with the new data obtained in 2013 • the realization of a descriptive statistical analysis of comments on the overall results according sleutelthematieken: age. sex. professional status, sector ... 0 evolution of the data. 2007_tot 2013 will also be analyzed and commented. comparisons in the extent possible from the results of the Belgian national survey conducted in 2010 with the collaboration of Eurofound (Dublin) • comparison to the extent possible the results with other Belgian data specifically on the three sectors