A longitudinal study on social, psychological, and physiological consequences of permanent night shifts and 12-hour shifts

  • Project number: F 2409
  • Institution: Federal Institute for Occupational Safety and Health (BAuA) / ars serendi GbR
  • Status: Completed Project


The aim of this research project was to investigate the short and long-term social, psychological, and physiological consequences of permanent night shifts and twelve-hour shifts. In addition to a literature review and a number of secondary data analyses, longitudinal studies with multiple measurement points were carried out at companies in the chemicals industry with comparable working conditions and employees doing similar work tasks. Apart from this, the longer-term impacts of permanent night work on employees were investigated. The project was conducted in cooperation with the Institute for Prevention and Occupational Medicine (Institut für Prävention und Arbeitsmedizin, IPA) and the Mining, Chemical and Energy Industrial Union (IG Bergbau, Chemie, Energie, IG BCE).

The literature review found that shift work generally and permanent night shifts especially are associated with more severe conflicts between work life and family life.

Results from the Federal Institute for Occupational Safety and Health (Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, BAuA) Working Time Survey show that, on average, permanent night workers report worse health. This is likewise reflected in some of the physiological markers looked at in the longitudinal studies. Despite this, permanent night workers are more satisfied with their work-life balance than employees who work rotating shifts. The study supplies evidence that social factors play a role in the choice of shift models and employees’ social lives are adapted to fit in with shift work.

The reconfiguration of shift systems may therefore have both positive and negative impacts on employees. Individuals who have been working under a particular shift system for a long time tend to evaluate such changes more negatively.

Some well-known recommendations about the best ways of organising shift work are confirmed by the study. Nevertheless, it also makes clear how varied the strains faced by individual shift workers are.

Additional analyses conducted in the course of the SARS-CoV-2 pandemic showed that the stress levels of the employees surveyed (measured by hair cortisol concentration) went up during the pandemic. This applies for all shift workers, regardless of the shift system.

Further research should, in particular, investigate the changing strains experienced by shift workers, with the organisational context being given particular attention in this respect.


Dauernachtarbeit in Deutschland

Publishing year: 2020

Suchergebnis_Format baua: Report brief

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Investigating the influence of shift work rosters on stress measured as cortisol in hair during the SARS-CoV-2 pandemic

Publishing year: 2022

Suchergebnis_Format Article

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Social jetlag and sleep debts are altered in different rosters of night shift work

Publishing year: 2022

Suchergebnis_Format Article

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Further Information


Unit 1.1 "Working Time and Flexibilisation"

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