Validity and reliability of the munsell soil color charts for assessing human skin color.

Abstract

Skin pigmentation is a key factor for ultraviolet radiation exposure-related cancers and can make a significant contribution to the patterns of other diseases. For surveys, and to appropriately target cancer control activities, valid and reliable measures of skin color are required. Validity and reliability of the Munsell Soil Color Charts were investigated for skin color assessment. The unexposed skin color of 280 university students was measured by spectrophotometer to calculate an Individual Typology Angle (ITA) value, and categorized by two independent raters according to the Munsell system (the latter was repeated after a 7-day interval). Interrater and intrarater reliability for the Munsell charts was found to be acceptable [intraclass correlation coefficients (ICC) of 0.85 and 0.86, respectively]. When ITA values were converted to the six Del Bino skin color categories, weighted κ for agreement between raters, within rater, and between Munsell chip and spectrophotometer were 0.63, 0.60, and 0.61, respectively. A tendency toward overestimation of the extremes of skin pigmentation was evident, particularly for the "brown" and "dark" skin types. Study findings suggest that the Munsell Soil Color Charts represent a reliable and valid measurement strategy when assessing skin type. The Munsell Year 2000 Soil Color Charts may provide a useful instrument for fieldwork contexts. Subsequent classification of individuals into skin cancer risk categories, rather than the use of precise ITA values, may be sufficient for targeting public health messages for skin cancer prevention and other health risks.