Objective: To validate a medication knowledge questionnaire in the adolescent high school student population.
Material and Methods: Location and sample: The data obtained in the study “Know me” were used for the above validation. Specifically, the response to the questionnaire at the first follow-up in the total number of students (n= 12,030). For the test-retest reliability test, the baseline and the first follow-up were used for the control group only (n= 6,228).
Data analysis: Reliability (internal consistency, two-half test and test-retest), validity (factor analysis) and item functioning (difficulty, discrimination and correlation with respect to the total questionnaire) were assessed.
Results: The reliability tests yielded results with indices all above 0.7. Thus, Cronbach’s alpha has a value of 0.80 and the test of two halves 0.81.
Validity shows a factor analysis that obtains its optimum in a solution of three factors, all of them with eigenvalues above 0.9 and explaining between the three a variance of 70% of the total.
As for the items, all of them present acceptable values of functioning in terms of difficulty and discrimination and a good correlation with respect to the total score of the questionnaire.
Conclusions: The knowledge questionnaire assessed in the present study has adequate metric properties and is useful for the intended purpose of assessing general knowledge about medicines in the population of high school students.