Beheshteh Malej Afzali; Ebrahim Hajizadeh; Fazlollah Ahmadi; Fazlollah Ghofranipour; Arezo Fallahi
Volume 21, Issue 1 , March and April 2015, , Pages 69-80
Abstract
Background: There is an absence of a valid and reliable tool basedon a field study for predictingfactors related to dental caries in adolescents. Also the lack of preventivemodels of tooth decay has been perceived. The aim of thisstudy was to design preventive models by assessing psychometric properties ...
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Background: There is an absence of a valid and reliable tool basedon a field study for predictingfactors related to dental caries in adolescents. Also the lack of preventivemodels of tooth decay has been perceived. The aim of thisstudy was to design preventive models by assessing psychometric properties of questionnaire of predictive factors for dental caries inadolescents using factor analysis.
Materials and Methods: This descriptive analytical research was done in 2013-14onadolescents who lived in Tehran city.First, model and questionnaire of predictive factors for dental caries in adolescents were designed based on qualitative research using grounded theory. Using systematic samplings,607 studentsand 400 students (12 and 16 years old) were selected for Exploratory Factor Analysis and Confirmatory Factor Analysis respectively. The reliability of the questionnairewas calculated by two different methods: Cronbach'salphaand test-retest. Also, in order to determine the validity of the scale, we used three methods including face validity, content validity, and construct validity. Exploratoryand ConfirmatoryFactorAnalysis were done bySPSS softwareversion 16 and LISLER softwareversion 8.8 respectively. Finally, appropriate models for preventing of tooth decay were presented.
Results: During exploratory factor analysis, eightfactors developed: behavioral factors, fear, social support, motivational beliefs, role of school, instructive elements, socio – economic status, and value of teeth. Results of confirmatory factor analysis showed that the eight-factor model for preventing of dental caries fit Iranian adolescents and the four-factor model isthe strongest predictor of oral health behaviorwhich foresees 76% of behaviors related to oral and dental health.Also test-retest scoreobtained 0.74 and internal consistency was 0.85.
Conclusion:Based on the results of this study, the validity and reliability of the38-item questionnaires of predictive factors for dental caries in adolescents is acceptable and suitable. Therefore the presented models can be used in designing educational programs. Also this tool can be applied in future researches and different groups of students.
Ebrahim Hajizadeh; AliReza Heidarnia; Shamsoddin Niknami; Mahmood Karimy
Volume 19, Issue 2 , May and June 2012, , Pages 190-197
Abstract
Background: Various studies all over the world have found support for the predictive validity of the theory of planned behavior with respect to smoking. In the absence of a valid and reliable theory of planned behavior (TPB) questionnaire for tobacco use in Iran, the purpose of this study was to design ...
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Background: Various studies all over the world have found support for the predictive validity of the theory of planned behavior with respect to smoking. In the absence of a valid and reliable theory of planned behavior (TPB) questionnaire for tobacco use in Iran, the purpose of this study was to design and assess the validity and reliability of the tobacco use theory of planned behavior scale in Iranian male adolescents. Materials and methods: Four hundred and seven students, aged between 14 and 19 years, served as the subjects of this study. They were selected through multi-stage random sampling. A questionnaire was designed based on Ajzen’s advice. The reliability coefficients were calculated by two different methods: Cronbach alpha and test-retest. Also, in order to determine the validity of the scale, we used three methods, including face validity, content validity, and construct validity. Results: Factor analysis showed that TPB consisted of 4 components (attitude, perceived control behavior, subjective norms, and intention), which explained 61% of common variance. Results show the total test-retest reliability and internal consistency to be 0.84 and 0.86, respectively. Confirmatory factor analysis results show that the four-factor model of TPB fits the Iranian sample. Conclusion: The validity and reliability of the Persian version of the tobacco use TPB scale were acceptable and suitable.