Development and Validation of the Health Literacy Scale for Workers

Background: Health literacy has received growing attention in recent years to reduce health disparities. Health literate individuals can gain access, understand and use health information to maintain, improve and promote good health. Objective: To develop and assess the psychometric properties of a tool for the measurement of health literacy among workers, the Health Literacy Scale for Workers (HELSW). Methods: 15 companies were selected from the factories of the industrial city of Saveh. 450 (400 male and 50 female) workers from Saveh, Iran, were selected through a multistage random sampling. The study had two stages—a qualitative and a quantitative stage. In the qualitative phase, the workers' beliefs were extracted based on 61 in-depth interviews. Content validity was assessed with the help of 12 experts in the field of health education, public health and occupational health. Also, face validity was evaluated through interviewing with 20 workers. In the quantitative phase, the reliability of the questionnaire was evaluated by measuring the internal consistency and test-retest reliability. The construct validity was assessed by the principal component analysis using varimax rotation. Results: In the exploratory factor analysis, six domains (ie, access, reading, understanding, assessment, decision making and applying health information, and self-efficacy) with 34 items were loaded; the model explained 64.3% of the total variance. Intraclass correlation coefficient and test-retest reliability ranged from 0.72 to 0.84 and 0.69 to 0.86, respectively. Conclusion: It seems that the developed Persian questionnaire, HELSW, is a reliable and valid measure of the health literacy in workers.