Development and validation of a skin health knowledge, attitudes, and behaviors questionnaire for the general population: a cross-sectional study.

BACKGROUND

Existing skin health assessments predominantly focus on single topics or diseases, making it difficult to cover the complete "Knowledge-Self-efficacy-Attitudes-Behaviors (KSAB)" continuum.

OBJECTIVE

To develop and validate a skin health knowledge, attitudes, and behaviors questionnaire for the general population.

METHODS

A cross-sectional online survey was conducted among the general population between October and November 2025. The questionnaire was developed based on a conceptual structure incorporating four dimensions: knowledge, self-efficacy, attitudes, and behaviors. Content validity was assessed by 13 experts, and the Item-level Content Validity Index (ICVI) and modified Kappa (K*) were calculated. Construct validity was examined using confirmatory factor analysis (CFA). Item-level evaluation was performed using item response theory (IRT), including the two-parameter logistic (2PL) model for dichotomous items and the graded response model (GRM) for ordered items.

RESULTS

A total of 865 individuals were enrolled (men: women = 1.24:1). Content validity was good (ICVI = 0.846-1.000, K* = 0.845-1.000). The five-factor model from CFA showed a good fit (CFI = 0.969, TLI = 0.960, RMSEA = 0.070, SRMR = 0.095). IRT analysis indicated that K1-K5 had acceptable discrimination (a = 0.59-2.40) and difficulty parameters ranging from -3.63 to -1.33. However, items K6, K7 and S1 were excluded due to insufficient threshold coverage. The proportion of women reporting frequent sunscreen use was higher than that of men. Self-efficacy levels showed a decreasing trend with age. Furthermore, individuals in service/manual labor occupations exhibited lower proportions on certain items.

CONCLUSION

This study developed and validated a KSAB questionnaire on skin health knowledge, attitudes, and behaviors, showing good validity and item-level performance. The findings support targeted health promotion for men, older adults, and service/manual workers.