Validity of the Fitzpatrick Skin Phototype Classification in Ecuador

BACKGROUND: The Fitzpatrick Skin Phototype Classification (FSPC) is the most common tool used to assess skin phototype in White populations according to the amount of pigment the skin has and its reaction to sun exposure. Scientific evidence about the use of this scale for persons with darker skin is limited. OBJECTIVE: To assess the internal consistency, reliability, and construct validity of the FSPC for Ecuadorians. METHODS: This observational cross-sectional study recruited participants of both sexes between 40 and 90 years of age living in a rural area of Quito, Ecuador. Cronbach α values were used to assess the internal consistency of the scale. Construct validity was assessed with confirmatory factor analysis. RESULTS: The internal consistency coefficients indicated that the reliability of the responses to the scale was fair. Total α value was .515, whereas the α values of the two factors were .42 and .67. Most item-to-factor correlations had a low to moderate magnitude, ranging from r = 0.30 to 0.37. Confirmatory factor analysis supported a two-factor solution and achieved good overall fit as indicated by root mean square error of approximation = 0.08, and nonnormed fit index = 0.88 was mediocre. Goodness-of-fit χ(2) = 177.10, P < .001. The factor loads were greater than 0.30, ranging from 0.30 to 0.99. CONCLUSIONS: The FSPC showed an acceptable construct validity and a fair internal consistency. The five-item scale could potentially be used as an effective instrument for assessing skin phototype in non-White people.