Reliability of the Demand-Control Questionnaire for sewing machine operators

The Demand-Control Questionnaire (DCQ), a 20-item scale that measures psychological work demands, job control and workplace social support, has frequently been used to assess occupational stress. The purpose of this study was to determine the test-retest reliability and internal consistency of the DCQ with sewing machine operators. Forty-six sewing machine operators completed the DCQ on two occasions with an 11-week time interval. A repeated measures analysis of variance model and subsequent application of generalizability theory were used to calculate the test-retest reliability of the subjects' ratings on the DCQ. Cronbach's alpha was used to determine the internal consistency of the scale. The test-retest reliability was 0.33 (95% confidence interval = 0.05-0.61), indicating fair reliability. Good internal consistency (Cronbach's alpha = 0.70) was found. The DCQ appears to be a reliable measure for assessing occupational stress in sewing machine operators. Workplaces need to place greater emphasis on the role of occupational stress in the prevention and treatment of musculoskeletal injuries among sewing machine operators.