Reliability assessment and validation of the dermal pigmentation area and severity index: a new scoring method for acquired dermal macular hyperpigmentation

Background Dermal pigmentation area and severity score ( DPASI ) is a recently proposed scoring system for acquired dermal macular hyperpigmentation ( ADMH ). Objective To determine the reliability and validity of DPASI . Methods After standardized training, three researchers independently rated 55 patients with ADMH on two consecutive days within 1 week, to determine intra‐rater and inter‐rater reliability. Validation was performed by comparing DPASI with the physician global assessment score. Results Test–retest reliability of individual raters tested by Pearson's r showed good correlation for all three raters ( r  = 0.984, P  < 0.0001; r  = 0.983, P  < 0.000 and r  = 0.970, P  < 0.0001). Inter‐rater agreement computed by intra‐class correlation coefficient also showed good correlation ( ICC  = 0.997, P  < 0.0001). Internal consistency as measured by Cronbach's alpha was 0.997. The score faired well in face and content validity (I‐ CVI of 0.87). On usability assessment, the scale had a median score of 4 on a scale from 1 to 5. The meantime taken to score the patients were 307.2 ± 83, 308.9 ± 84.4, 350.15 ± 91.8 s by three observers, respectively. Conclusion The DPASI is a reliable measure of ADMH severity. The use of dermoscopy decreases inter and intra‐observer variation resulting in a more objective score.