A study examining inter- and intrarater reliability of three scales for measuring severity of psoriasis: Psoriasis Area and Severity Index, Physician's Global Assessment and Lattice System Physician's Global Assessment

Each one of the three scales provided reproducible psoriasis severity assessments. In terms of both intrarater and inter-rater reliability values, the three scales can be ranked from highest to lowest as follows: PASI, LS-PGA and PGA.