Objective
Chronotype is a personal characteristic affecting an individual’s adaptability to shift work. The present study aimed to investigate the relationship between chronotype, shift work-related health disorders and sleep quality in shift workers in the petrochemical industry in southern Iran.
Design
This was a cross-sectional study.
Site
The study was conducted in a petrochemical complex located in southern Iran.
Participants
250 male shift workers with at least five years of shift work experience, no major physical or mental health issues, and no use of alcohol, drugs, or sleep medications.
Interventions
No interventions were applied, as this was an observational cross-sectional study.
Main measurements
Data were collected using the Shift Work Impact on Health and Social Disorders (SOS) Questionnaire, the Pittsburgh Sleep Quality Index (PSQI), the Morningness–Eveningness Questionnaire (MEQ), and the Cognitive Failure Questionnaire.
Results
The prevalence of musculoskeletal, gastrointestinal, and cardiovascular disorders was significantly higher in morning types than evening types (p<0.05). Cognitive failures and sleep quality also differed significantly between the two groups (p<0.05).
Conclusions
Evening-type individuals showed higher adaptability to shift work and lower vulnerability to negative consequences. Circadian typology should be considered when assigning workers to shifts, especially for sensitive jobs.