Testing and validation of the questionnaire for evaluating the chemical composition of bottled water in relation to public health

Introduction. In the context of increasing global consumption of bottled water, assessing its chemical composition and impact on public health becomes essential. Although perceived as a safe alternative, bottled water exhibits variability in its chemical composition, and advanced filtration methods can remove essential minerals. Consumers opt for bottled water due to its taste and convenience, yet awareness of associated risks remains limited. This study proposes the development and validation of a questionnaire to evaluate public perceptions of bottled water quality and its health impact, providing a valuable tool for public education and regulatory policies. Material and methods. The questionnaire was developed to analyze consumer attitudes and behaviors regarding bottled water. Structured into four sections (socio-demographic data, consumption habits, perceptions of quality, and health impact), it underwent multiple validation stages. A panel of experts assessed the relevance of the questions, and a pilot study was conducted with a sample of 32 adults (aged 24-62) to evaluate validity and internal consistency using the Cronbach’s alpha coefficient. Final validation was based on the feedback collected and statistical analysis performed using SPSS Statistics 27. Results. S-CVI/Ave and S-CVI/UA are indicators of questionnaire content validity, calculated based on item validity scores and the percentage of agreement among evaluators. The S-CVI/Ave and S-CVI/UA values exceeded the minimum standard of 0.80, while the I-CVI index ranged between 0.83 and 1.00, demonstrating excellent item validity. Following respondent feedback, 18 questions were revised, and 6 were removed, resulting in a second version with 61 items. The validity sample comprised 84.4% women and 15.6% men, aged 24 to 62 years. Most respondents considered the questions clear and easy to understand, although suggestions were made to improve clarity and avoid redundancy. Internal consistency was confirmed through the Cronbach’s alpha coefficient, which was acceptable for most domains, except one, where the coefficient was below 0.70 but was retained due to the validity of the questions. Conclusions. The questionnaire for assessing bottled water consumption was successfully validated, demonstrating content validity and internal consistency. Face validity ensured the clarity of the question.