Comment: Evaluation of therapeutic response of methotrexate and calcipotriol combination compared with methotrexate alone in plaque psoriasis

We write to express our concerns on the adoption of only physician-rated outcome measurement, namely the Psoriasis Area and Severity Index, in this otherwise exceptionally well conducted randomised controlled trial, without the adoption of any patient-rated outcome variable, such as quality of life (QOL) indexes. Skin diseases might cast very significant impacts on the quality of life of patients. However, symptoms and impacts on the QOL are known to be not necessarily correlate directly with disease severity as rated by physicians for skin diseases [1, 2], including psoriasis vulgaris [3]. QOL indexes, such as the Dermatology Life Quality Index [4] and the Children Dermatology Life Quality Index [5], have been constructed, validated, and validly translated into a large number of languages [1, 6, 7]