What do Hyperhidrosis Quality of Life Index (HidroQoL?) scores mean? Transferring science into practice by establishing a score banding system

Background The Hyperhidrosis Quality of Life Index (HidroQoL (c)) is a measure of quality of life (QoL) impacts in hyperhidrosis (HH).Objectives We aimed to establish score banding systems for the HidroQoL total score for specific contexts representing different severity/impact categories by using the Dermatology Life Quality Index (DLQI) and the Hyperhidrosis Disease Severity Scale (HDSS) as anchors, including data from 357 patients from a phase III clinical trial.Methods We used the HDSS, the established DLQI score bands and two single items (items 5 and 7) of the DLQI as anchors for the creation of banding systems for the HidroQoL. These anchors were chosen via consensus among an expert group according to relevance to patient experience. Due to the distribution of the HDSS and the single DLQI item 7, receiver operating characteristic curves were computed in order to create an optimal cut-off value of the HidroQoL total score. For the DLQI banding system and the single DLQI item 5, we created a banding system for the HidroQoL based on the distribution of their different categories.Results A score of 30 and greater is proposed as the cut-off value for sweating that 'always interferes in daily activities', based on the HDSS as anchor. In terms of overall skin QoL effects, score bands of 0-6, 7-18, 19-25, 26-32 and 33-36 represent 'no effect', 'small effect', 'moderate effect', 'very large effect' and 'extremely large effect' on the patient's life, respectively.Conclusions In this study, we propose different banding systems for four different contexts: skin-specific QoL (DLQI banding), HH severity (HDSS), working and studying (single DLQI item 7) and social and leisure activities (single DLQI item 5). These banding systems and cut-off values can be used in clinical research and practice to place the patients in different severity categories.