Psychometric properties of a new questionnaire for evaluating the literacy of parents concerning children's oral health (POHeLM)

Parents' oral health literacy may be a reliable predictor of children's oral health. Therefore, the present study was conducted to develop and validate a questionnaire to assess parents' oral health literacy about their children's oral health. This study was conducted from April 2020 until October 2020. Questionnaire items were developed by evaluating  content validity based on expert opinions, content validity ratio, and content validity index, and cognitive interview. Random sampling was used to recruit a total of 500 patients from referral hospitals in the city of Kerman. Based on factor analysis, construct validity included exploratory factor analysis via SPSS software version 22, and confirmatory factor analysis via Mplus software version 7.4. The invariance of the model evaluation and the evaluation of the reliability of the questionnaire were assessed based on Cronbach's alpha coefficient. First, 71 items were chosen for evaluation, and then 19 items were promoted to the next stage, based on the content validity coefficients. The results of the exploratory factor analysis led to the extraction of a three-factor model of Parent's Oral Health Literacy Measure (POHeLM) about children's oral health. These three factors explained 56% of the total variance of the questionnaire altogether. These three factors include the accessibility domain (two items), the utilization domain (eleven items), and the communication domain (six items). Model fit indices based on confirmatory factor analysis confirmed the proper fit of the three-factor model. Also, in measuring the factor invariance, the model's validity in both male and female was authenticated. The Cronbach’s alpha coefficient was calculated as 0.81.  This study shows that the POHeLM questionnaire possesses appropriate validity and reliability by 19 questions and 3 subclass.