Validity and Reliability of the Persian Translation of the World Health Organization (WHO) Oral Health Self-assessment Questionnaire for Children and Adolescents

Background: Regularly assessing the oral health of children and adolescents is crucial. Researchers seek valid and reliable questionnaires to obtain comparable global data, enabling oral health evaluation in large populations, remote regions, or even during an epidemic like COVID-19, while saving time and money. Objectives: The present study was conducted to translate and validate the Persian version of the World Health Organization (WHO) Oral Health Self-assessment Questionnaire for Children and Adolescents. Methods: In 2022, a cross-sectional study was conducted in Kerman, Iran. The Persian questionnaire was tested on 20 individuals to assess the fluency and clarity of the Persian translation. The questionnaire was then filled out by 40 individuals, and reliability was evaluated using the test-retest method. The final questionnaire was completed by 878 randomly selected participants aged 7 - 18 years online. To establish concurrent validity, the researchers added three questions related to the presence of toothache without dental visits, filled teeth, and teeth with endodontic treatment. Internal consistency was checked by calculating Cronbach's alpha coefficient. Results: A total of 290 students aged 7 to 12 and 588 students aged 13 to 18 participated in the study. Cronbach’s alpha for the entire questionnaire was 0.656 for students under 12 years old and 0.643 for those over 12 years old. The intra-cluster correlation coefficient for both age groups was between 0.81 and 0.87. Examining the concurrent validity of this questionnaire showed that the three additional questions added by the researchers have a significant relationship with the questions describing the health of teeth and gums (oral health), the number of times participants felt toothache in the last 12 months, and the problem of biting and chewing. However, they had no significant relationship with the risk factor related to nutrition. Moreover, the questionnaire is multifactorial. Conclusions: The Persian version of the WHO Oral Health Self-assessment Questionnaire for Children and Adolescents is reliable over time. If the questionnaire is repeated and the responses of people in the same population are collected, it yields similar results. It has internal consistency, but it is a multi-factor questionnaire.