Factor structure of Zung self-rating depression scale for workers

Area of Science:

• Occupational Health
• Psychological Assessment
• Sociology

Background:

• Night-shift work is common in industries like railways.
• Assessing depression in shift workers is crucial for occupational health.
• The Zung Self-Rating Depression Scale (SDS) is a widely used tool for measuring depressive symptoms.

Purpose of the Study:

• To investigate the factor structure of the Zung Self-Rating Depression Scale (SDS) in night-shift railway workers.
• To compare the SDS factor structure between night-shift and daytime workers.
• To explore the relationship between age and depression scores in this population.

Main Methods:

• A cross-sectional study involving 1,784 night-shift railway workers and 1,394 daytime controls.
• Administration of the Zung Self-Rating Depression Scale (SDS).
• Factor analysis was performed to determine the underlying structure of the SDS items.

Main Results:

• The average age of participants was 39.9 years.
• A significant inverse correlation was observed between age and SDS index.
• Factor analysis revealed two main factors (positive and depressive items), explaining similar variance (18.2% and 18.1%).
• Four specific items did not form distinct factors.
• The factor structure of the SDS was comparable between night-shift and daytime workers.

Conclusions:

• The Zung Self-Rating Depression Scale (SDS) demonstrates a similar factor structure in both night-shift and daytime railway workers.
• Depression symptoms, as measured by the SDS, tend to decrease with increasing age in this occupational group.
• Further research may explore the specific items that did not load onto distinct factors.