Psychometric Properties of the Revised Osteoporosis Knowledge Test in Iranian Adolescent

Background: Osteoporosis knowledge test is a comprehensive questionnaire that evaluates risk factors, nutrition and exercise recommendations, as well as general subjects such as bone evolution, diagnosis, and osteoporosis treatment. The aim of this study was to determine the psychometric characteristics of the revised version of osteoporosis knowledge test (OKT) in Iranian adolescent population. Materials and Methods: This is a cross-sectional methodological study that studied 330 high school students. Sampling was conducted in public and private schools in Saveh, Iran. Schools and students in each school were randomly selected.The translation validity was examined using Forward and Backward translation. Content validity was examined in two qualitative (assessment of experts’ opinions) and quantitative (using the content validity ratio (CVR) and Content Validity Index [CVI]) parts. Face validity was determined on 30 high school students. The generalized factor analysis (GFA) was used to evaluate the construct validity of the instrument. The reliability was determined in terms of reproducibility via intra-class correlation coefficient (ICC) by test–retest and internal consistency (Cronbach’s alpha) on 20 participants. Results: Content validity indices, CVI and CVR, for OKT were 0.97 and 0.99, respectively. Reliability was confirmed in two dimensions of intra-class correlation coefficient (ICC = 0.69), and internal consistency (α = 0.81). Construct validity was confirmed using the generalized factor analysis. Conclusion: Findings support the validity and reliability of osteoporosis knowledge test. Therefore, it is recommended that the instrument can be used in both clinical practice and research in Iranian adolescent population.