Assessing uptake of the Harmonising Outcome Measures for Eczema (HOME) Core Outcome Set and recommended instruments

The Harmonising Outcome Measures for Eczema (HOME) initiative has recommended a Core Outcome Set (COS) for atopic eczema clinical trials1 . Adherence to this COS in future clinical trials of atopic eczema treatments will ensure outcomes are measured and reported consistently, thus allowing direct comparison and minimising bias2 . The COS consists of domains (what should be measured) and instruments (how to measure it). In 2011 four core domains were agreed i) clinician-reported signs, ii) patient-reported symptoms, iii) dermatology-specific quality of life (QoL) and iv) long-term control. EASI (Eczema Area and Severity Index, 2013) and POEM (Patient Oriented Eczema Measure, 2015) are the agreed instruments for signs and symptoms, respectively. EASI combines the severity of the signs of eczema with the extent to which the body is affected3 , and POEM is a seven-item questionnaire that captures the frequency of symptoms of eczema experienced over the previous week4 . Using the WHO International Clinical Trials Registry Platform (ICTRP), a network of international clinical trials registers, we sought to quantify uptake of the HOME core outcomes in clinical trials over time.

Assessing uptake of the Harmonising Outcome Measures for Eczema (HOME) Core Outcome Set and recommended instruments DOI: 10.1111/bjd.19030 DEAR EDITOR, The Harmonising Outcome Measures for Eczema (HOME) initiative has recommended a Core Outcome Set (COS) for atopic eczema clinical trials. 1 Adherence to this COS in future clinical trials of atopic eczema treatments will ensure outcomes are measured and reported consistently, thus allowing direct comparison and minimizing bias. 2 The COS consists of domains (what should be measured) and instruments (how to measure it). In 2011 four core domains were agreed: (i) clinician-reported signs, (ii) patient-reported symptoms, (iii) dermatology-specific quality of life (QoL) and (iv) long-term control. The Eczema Area and Severity Index (EASI) (2013) and Patient-Oriented Eczema Measure (POEM) (2015) are the agreed instruments for signs and symptoms, respectively. EASI combines the severity of the signs of eczema with the extent to which the body is affected, 3 and POEM is a seven-item questionnaire that captures the frequency of symptoms of eczema experienced over the previous week. 4 Using the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), a network of international clinical trials registers, we sought to quantify uptake of the HOME core outcomes in clinical trials over time.
We included Phase III/IV treatment trials involving adults and/or children with atopic eczema registered within the WHO ICTRP between 24 January 2005 and 16 June 2018. We excluded trials of interventions for primary eczema prevention and those that never commenced. We independently screened records for eligibility (C.McW. and R.V.) and extracted data for signs, symptoms and skin-related QoL domains. The long-term control domain was excluded because the HOME group had not defined this domain when we conducted our review. At the instrument level, EASI and POEM uptake was explored for clinician-reported signs and patientreported symptoms, respectively. To assess change over time, trials were ordered by registration date and divided into 5year blocks, from which the percentage of trials reporting the COS over the previous 5-year period was calculated (Figure 1).
We found an increase in the proportion of atopic eczema treatment trials that included the recommended domains of signs, symptoms and dermatology-specific QoL, with uptake of the specific instruments of EASI and POEM. The overall increase in patient-reported symptoms and QoL could reflect increasing recognition of the importance of patient-reported outcomes in trials. Uptake of the QoL domain has remained low. It is worth noting that QoL instruments were recommended in 2019, 1 after our data collection had taken place.
The inclusion of core domains in atopic eczema trials was already increasing at the time of the initial HOME domain recommendations in 2012. This may be because the eDelphi consensus on domains published in 2010 encouraged their inclusion even before the HOME consensus publication in 2012. 5 While uptake of a COS and associated instruments is a step forward it is not, by itself, sufficient. Unless domains and instruments are measured at comparable time points and data presented in a suitable format for meta-analysis, difficulties in synthesizing data will remain. HOME have begun to address this by recommending that all trials, for each primary outcome, report mean and standard deviation at baseline and end of treatment as a minimum. 6 In summary, we present a systematic assessment of the uptake of the HOME COS. The published COS and instruments, agreed by a consensus methodology encompassing all stakeholders in the decision-making process, appears to have supported adoption of the HOME recommendations by the research community. Other COS development groups should be encouraged by these findings. Further work is needed by funders, journal editors and systematic reviewers to promote and mandate use of COSs. For MMS, the majority of responders in BSDS and ACD are using chlorhexidine-based antiseptics for the head including ear, neck and below (Table 1). In the periocular region, BSDS responders prefer normal saline (50% layers, 47% repairs) followed by iodine-based (26% layers, 26% repairs) and chlorhexidine-based (24% layer, 26% repairs) antiseptics. ACD preference in the periocular area was iodine-based (40% layers, 40% repairs) or normal saline (36% layers, 40% repairs), with a minority still using chlorhexidine-based (24% layers, 24% repairs) antiseptics.
In each of the BSDS and ACD, comprising approximately 6500 and 8000 cumulative MMS cases annually among responders, respectively, chlorhexidine-based antiseptics were reported as causing two and one case of ocular irritation, and two and five cases of skin irritation, respectively. Iodine-based antiseptics were reported as causing one case of skin irritation in BSDS and three cases in ACD.
A total of 62% of BSDS and 20% of ACD responders were not aware of the recent review 2 highlighting the risks of chlorhexidine-based antiseptics. Four BSDS responders and one ACD responder reported that in the last 12 months, they have reduced chlorhexidine-based antiseptic use on the head region. One ACD responder also reported changing to using chlorhexidine in an alcohol base, although our study did not specifically seek details of the base of chlorhexidine used, being either alcohol or aqueous.
A similar study by Collins et al. 3 was completed in American College of Mohs Surgery (ACMS) members in 2015 with 168 responses (estimated 10% response rate). ACMS members are primarily working privately (75%) and performing over 500 MMS cases annually (48%). 3 Similar to BSDS and ACD, members of ACMS 3 follow the trend of preferring chlorhexidine-based antiseptics in all sites excluding periocular, with a smaller proportion (18% layers, 19% repairs)