Open Access Open Badges Research article

Development and validity of a questionnaire to test the knowledge of primary care personnel regarding nutrition in obese adolescents

Lucinéia de Pinho*, Paulo Henrique Tolentino Moura, Marise Fagundes Silveira, Ana Cristina Carvalho de Botelho and Antônio Prates Caldeira

Author Affiliations

Health Sciences Postgraduate Program, State University of Montes Claros (Unimontes), Montes Claros, MG, Brazil

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BMC Family Practice 2013, 14:102  doi:10.1186/1471-2296-14-102

Published: 18 July 2013



In light of its epidemic proportions in developed and developing countries, obesity is considered a serious public health issue. In order to increase knowledge concerning the ability of health care professionals in caring for obese adolescents and adopt more efficient preventive and control measures, a questionnaire was developed and validated to assess non-dietitian health professionals regarding their Knowledge of Nutrition in Obese Adolescents (KNOA).


The development and evaluation of a questionnaire to assess the knowledge of primary care practitioners with respect to nutrition in obese adolescents was carried out in five phases, as follows: 1) definition of study dimensions 2) development of 42 questions and preliminary evaluation of the questionnaire by a panel of experts; 3) characterization and selection of primary care practitioners (35 dietitians and 265 non-dietitians) and measurement of questionnaire criteria by contrasting the responses of dietitians and non-dietitians; 4) reliability assessment by question exclusion based on item difficulty (too easy and too difficult for non-dietitian practitioners), item discrimination, internal consistency and reproducibility index determination; and 5) scoring the completed questionnaires.


Dietitians obtained higher scores than non-dietitians (Mann–Whitney U test, P < 0.05), confirming the validity of the questionnaire criteria. Items were discriminated by correlating the score for each item with the total score, using a minimum of 0.2 as a correlation coefficient cutoff value. Item difficulty was controlled by excluding questions answered correctly by more than 90% of the non-dietitian subjects (too easy) or by less than 10% of them (too difficult). The final questionnaire contained 26 of the original 42 questions, increasing Cronbach’s α value from 0.788 to 0.807. Test-retest agreement between respondents was classified as good to very good (Kappa test, >0.60).


The KNOA questionnaire developed for primary care practitioners is a valid, consistent and suitable instrument that can be applied over time, making it a promising tool for developing and guiding public health policies.

Adolescent nutrition; Questionnaire; Validity; Primary healthcare