[Core outcome measurements in hand eczema trials : The HECOS initiative]

To enhance the informative value and comparability of hand eczema trials, the consensus of a set of core outcomes is necessary.

How is success of therapeutic and preventive interventions currently determined in hand eczema trials? Which standard should apply in the future?

As a first step, a systematic literature review was conducted to describe the status in controlled and randomized-controlled hand eczema trials from 2000-2017 and to identify the applied outcomes. The Hand Eczema Core Outcome Set (HECOS) initiative follows the guidelines of the Cochrane Skin Group Core Outcomes Set Initiative (CS-COUSIN) so that its further process is going to ensure the validity of the proposed measurement instruments and the appropriate inclusion of patients', physicians', and researchers' perspectives.

Previous trials predominantly assessed erythema, scaling, fissures, vesicles, or pruritus as clinical signs and symptoms of hand eczema. These variables were often not reported separately but as part of a variety of scores. Only few hand eczema scores were applied in more than one trial-most commonly the Hand Eczema Severity Index (HECSI, in 10% of the trials). Overall skin condition, without mentioning specific signs or symptoms, was assessed in 51% of the trials.

Although certain clinical signs and symptoms were assessed by a majority of hand eczema trials, comparability of results was not ensured because various measurement instruments were applied. HECOS is going to agree on a set of relevant and valid core outcome measurement instruments.