[Study on the development of public health and safety literacy assessment scale for university freshmen]

Objective: To develop a measurement scale for the public health and safety literacy of university freshmen. Methods: Item pooling was conducted through literature review and in-depth interview with public health experts, and a nominal group was organized to develop the initial items to form the questionnaire. A total of 250 freshmen were randomly selected to complete the questionnaire, and the assessment of psychometric properties were performed to carry out item reduction by using classical test theory and item response theory. Exploratory factor analysis method (EFA) was employed to calculate the item-factor loadings. The data collected from another 318 freshmen were analyzed using confirmatory factor analysis method (CFA). Results: The scale contained 3 dimensions and 9 items with all content validity index ≥0.8. The difficulty coefficient of 9 items was 1.18-2.43. The discriminative validity analysis showed that the difficulty index was 0.41-0.78, and the discrimination index was 0.38-0.64. Each of the remaining items had a statistically significant difference in the score value between the top 27% and lowest 27% of respondents (t>3, P<0.05). The item's Cronbach's α was 0.72-0.77, corrected item-total correlation was 0.33-0.60 and the overall α of the scale was 0.77. EFA indicated all item-factor loading were higher than 0.680, and the accumulated variance contribution of the 3 factors was 62.484%. Results of CFA showed that the overall fitness index of the model reached the fitness standard except for the χ value. There was no statistical significance in the total score of the scale and the scores of each item among groups with different demographic characteristics (P>0.05). Conclusions: The newly developed public health safety literacy scale had a good reliability,validity,stability and item constancy.It can be used in measurement of the public health and safety literacy of university freshmen.