Design and validation of the Lifestyle Screening Questionnaire in Adolescents (LSQA)

Introduction and objective: In the literature, various questionnaires and surveys have been developed to assess adolescents' lifestyles; however, the vast majority require a long time to administer, making their use in school environments complicated. This study focuses on designing and validating the Lifestyle Screening Questionnaire for Adolescents (LSQA). Methodology: The LSQA was administered to 603 Spanish adolescents and re-administered after 15 days. The Global School Health Survey (GSHS) was also administered. Content validity (Content Validity Coefficient, CVC) and criterion validity (Spearman correlations) were used to assess validity. Reliability was evaluated using test-retest methods (Spearman correlation), and the internal consistency of the questionnaire was evaluated using Cronbach’s alpha and intraclass correlation coefficients (ICC). Results: Content validity was assessed by a panel of experts, with a CVC greater than 0.900 in all cases, demonstrating excellent validity and agreement. Criterion validity showed that the instrument measures relevant constructs consistent with the GSHS dimensions. Internal consistency was considered satisfactory (α = 0.540–0.882) with an ICC > 0.50. Test-retest reliability demonstrated good stability (r > 0.50). The final questionnaire included seven dimensions and 56 items. Conclusions: The findings support the use of LSQA as a valid and reliable tool for assessing habits and lifestyles in adolescents.