Development and validation of a questionnaire to assess adolescents’ knowledge, attitude, norms and media literacy related to sugar-sweetened beverages

The high consumption of sugar-sweetened beverages (SSB) among adolescents has become a growing public health concern in Malaysia due to its strong association with obesity, diabetes, and other non-communicable diseases. Despite increasing awareness, there is a lack of validated assessment tools that comprehensively capture the factors influencing adolescents' perceptions of SSB, particularly in the local cultural context. To bridge this gap, this study aimed to develop and validate a culturally appropriate questionnaire to assess adolescents’ knowledge, attitude, norms and media literacy of SSB in Malaysia, focusing on four key domains: knowledge, attitude, norms, and media literacy. The development of the questionnaire was motivated by the absence of a validated, knowledge, attitude, norms and media literacy-based tool suitable for local adolescents, despite the growing concern over rising SSB consumption and childhood obesity in the country. The validation process involved three main phases: content validity, face validity, and test-retest reliability. For content validity, nine experts evaluated the relevance of each item using the Item- Level Content Validity Index (I-CVI) and Scale-Level Content Validity Index (S- CVI/Ave), with results showing excellent overall agreement (S-CVI/Ave = 0.91). Face validity was conducted among 10 secondary school students, and the clarity and comprehensibility of items were confirmed with I-FVI/Ave scores of 0.91 and 0.90, respectively. Test-retest reliability was assessed among 134 students using Cronbach’s alpha, Cohen’s Kappa, and Intraclass Correlation Coefficient (ICC), revealing moderate reliability across all domains. While the instrument demonstrated acceptable validity and practical usability, the internal consistency of some domains indicated a need for refinement in future applications. This newly developed questionnaire offers a reliable and culturally relevant tool for evaluating adolescents’ knowledge, attitude, norms and media literacy of SSB and may support future interventions, public health research, and education programs targeting dietary behaviour in Malaysian youth.