Development and validation of a sunlight exposure questionnaire for urban adult Filipinos.

Purpose: To develop and validate a self-reported sunlight exposure questionnaire (SEQ) for urban adult Filipinos.

Methods: The study included adults (19-76 years old) in Metro Manila, Philippines, well-versed in the Filipino (Tagalog) language and residing in an urban area for at least 1 year. Exclusion criteria included pregnancy, active skin disorders, and immunocompromised states. An expert panel created a questionnaire in Likert scale format based on a conceptual framework and four existing instruments. The study proceeded in four phases: questionnaire item development, translation and back-translation, pretesting, and construct validity and reliability testing using factor analysis, Cronbach's-alpha coefficient, and the paired t-test.

Results: A 25-item, self-administered, Filipino (Tagalog) SEQ answerable by a 4-point Likert scale was created. The questionnaire was administered to 260 adult participants twice with a two-week interval, with all participants completing both the first and second testing. All questionnaire items possessed adequate content validity indices of at least 0.86. After factor analysis, three questionnaire domains were identified: intensity of sunlight exposure, factors affecting sunlight exposure, and sun protection practices. Internal consistency was satisfactory for both the overall questionnaire (Cronbach's-alpha 0.80) and for each of the domains (Cronbach's-alpha 0.74, 0.71, and 0.72, respectively.) No statistically significant differences were observed in the responses between the first and second tests, indicating good test-retest reliability.

Conclusion: We developed a culturally-appropriate SEQ with sufficient content validity, construct validity, and reliability to assess sunlight exposure among urban adult Filipinos in Metro Manila, Philippines.