Designing a standard Persian questionnaire to evaluate knowledge of school hygiene instructors about dental trauma

A standardized questionnaire is the principal tool for assessing individuals’ knowledge. Since no standard questionnaire is available for assessing elementary school hygiene instructors’ knowledge about dental taumas the aim of this study was to design and standardize such a questionnaire with acceptable validity and reliability.

In the present descriptive study in order to design a standard questionnaire, existing questions about individuals’ knowledge on dental trauma were evaluated from papers published in English and 42 questions were selected. The English questions were translated into Persian in a linguistic style. The validity of the questions was fully evaluated by experts in epidemiology, Persian language, pedodontists and endodontics, considering the target group and a Persian questionnaire was prepared. In order to evaluate the reliability of the designed questionnaire, 30 hygiene instructors from Shiraz elementary schools were asked to answer the questionnaire. Inter-item correlation, Cronbach's alpha and alpha when the item was deleted, were used along with intra-class correlation test with SPSS 18. All the necessary changes were made and validity and reliability tests were repeated until appropriate results were achieved.

Assessment of the reliability of the questionnaire was carried out twice, which resulted in a questionnaire with 19 multiple choice questions. Cronbach’s alpha of the final questionnaire was 0.887 and ICC was 0.716. No significant change was observed after deleting each question.

Under the limitations of the present study, it can be concluded that a standardized Persian questionnaire, including 19 questions with acceptable validity and reliability is now available to evaluate school hygiene instructors’ knowledge about dental trauma and can be used in other similar studies in Iran.