Reliability Assessment and Validation of the Skin Hyperpigmentation Index Compared to the Physician Global Assessment Score.

BACKGROUND

The skin hyperpigmentation index (SHI), a new objective method for measuring skin hyperpigmentation, needs validation.

OBJECTIVE

To gain evidence of the reliability and validity of the SHI.

METHODS

Fifteen raters were divided into 3 groups (5 dermatologists, 5 nondermatologist physicians, and 5 nonphysician clinicians). Each rated 5 pigmented mole lesions with mild-to-severe hyperpigmentation to determine intra- and interrater reliability. All raters photographed the lesions and rated them using the subjective Physician Global Assessment (PGA) score. The same photographs were then assessed based on automatic computer measurement software using the online SHI tool (https://shi.skinimageanalysis.com).

RESULTS

The SHI reliability was excellent for all intra- and interrater assessments, while most PGA assessments showed good intra- and interrater agreement. Between-group reliability was excellent for SHI, while moderate-to-good for PGA evaluations. Concordance between the SHI and PGA assessments was strong across all groups of assessors.

CONCLUSION

There is evidence that the SHI is a reliable instrument for measuring skin hyperpigmentation, and can be used by nonexperienced clinicians.