Development and evaluation of an infectious disease-specific health literacy scale

Objective To develop a scale for assessing infectious disease-specific health literacy (IDSHL) among Chinese residents and to evaluate reliability and validity of the scale.Methods Based on the definition of health literacy defined by World Health Organization,the conceptual construction of the scale was built.Exploratory factor analysis (EFA),principal component analysis (PCA) and reliability and validity test were used to assess psychometric properties of the scale.Totally 8 858 adult residents were sampled from Jiaxing city of Zhejiang province,Yichang city of Hubei province and Lanzhou city of Gansu province to test the appropriateness of the scale between September and December,2013.Results A scale with 28 items in 2 parts was constructed based on the results of EFA and PCA.For the scale finally established,the four dimensions (22 items) in the subscale A are knowledge and concept (7 items),disease prevention (7),disease management and treatment (4),and cognition on pathogen and source of infection (4),and the accumulated variance contribution of the 4 dimensions was 46.273%;the Cronbach's α values of the four dimensions were 0.652,0.672,0.599,and 0.632 and the corrected item-total correlation (CITC) of the 4 dimensions were 0.620,0.715,0.523,and 0.587,respectively.The difficulty coefficients of the 22 items ranged from 1.19 to 4.08,suggesting a good reliability of the subscale A;the content validity indexes were ≥0.8 for all the 22 items in the subscale A,demonstrating a good content validity.There were statistically significant differences in the total score of the IDSHL scale among the residents with different socio-economic characteristics,including gender,age,education level,marital status,occupation,health status,2-week morbidity,average time of daily internet browsing,and the way of information acquisition (P<0.001 for all),indicating a good discriminate validity of the subscale.The subscale B,consisting of 4 items for cognition on individualized health information,showed a good discriminate validity,with significantly higher average scores of 24.67±6.82,25.05±6.56,23.30±7.23,and 24.32±6.74 among the residents answering 4 items correctly than those of 20.17±8.12,20.95±8.09,17.07±8.59,and 18.28±8.29 among the residents having no correct answers to the 4 times,respectively (all P<0.001).Conclusion The established 28-item IDSHL scale is of good reliability and validity and could be used as a simple instrument for measuring infectious disease-specific health literacy and efficacy of intervention on infectious disease among Chinese residents.