Core outcome domains for controlled trials and clinical recordkeeping in eczema: international multiperspective Delphi consensus process

There is wide variation in the use of outcome measures for eczema. We performed a three-stage web-based international Delphi exercise to develop consensus-based sets of core outcome domains for eczema for "controlled trials" and "clinical recordkeeping". A total of 57 individuals from four stakeholder groups (consumers, clinical experts, regulatory agency representatives, and journal editors) representing 13 countries were asked to rate the importance of 19 outcome domains for eczema and to choose which domains should be included in two core sets of outcomes. Forty-six individuals (81%) participated. Participants received standardized feedback, including the group median, interquartile range, and previous responses, and the assessment was repeated in two subsequent rounds. We defined consensus a priori if at least 60% of the members of at least three stakeholder groups, including consumers, recommended domain inclusion in the core set. Consensus was achieved for inclusion of symptoms, physician-assessed clinical signs, and a measurement for long-term control of flares in the core set of outcome domains for eczema trials. We recommend including these three core outcomes in future eczema trials in order to enhance clinical interpretability and to enable meta-analyses across different studies. For recordkeeping, consensus was reached to regularly monitor eczema symptoms in clinical practice. Future work is needed to select which existing or new scales should be used to measure the domains identified as relevant for the core set.


To achieve better standardization in the outcomes applied in clinical research and practice, we performed and moderated an international multiperspective Delphi consensus project to develop core sets of outcome domains for eczema for controlled trials and for recordkeeping in clinical practice.


Schmitt, Jochen Langan, Sinead Stamm, Tanja Williams, Hywel C. Harmonizing Outcome Measurements in Eczema Delphi, panel


Journal: Journal of Investigative Dermatology
Volume: 131
Issue: 3
Pages: 623 - 30
Year: 2011
DOI: doi:10.1038/jid.2010.303

Further Study Information

Current Stage: Not Applicable
Date: June 2008 - March 2010
Funding source(s): The study was planned, performed, and analyzed independently without involvement of external funding.

Health Area

Disease Category: Skin

Disease Name: Eczema

Target Population

Age Range: Unknown

Sex: Either

Nature of Intervention: Any

Stakeholders Involved

- Consumers (patients)
- Regulatory agency representatives
- Journal editors
- Clinical experts
- Consumers (caregivers)

Study Type

- Prioritising
- COS for clinical trials or clinical research
- COS for practice


- Delphi process

Three stage, web based, international Delphi consensus exercise.

To provide an evidence base for the consensus, we systematically collected, summarized, and critically appraised all named eczema outcome scales in the run-up to the Delphi project (Schmitt et al., 2007). This review identified 20 named outcome measurements for eczema that covered the domains of clinical signs, disease extent, symptoms, involvement of visible areas such as the face, course of disease, global disease severity, and epidermal function. Assessment of content validity by 12 consumers (four patients with eczema, aged 18 years; four affected children/adolescents, aged 8–14 years; four caregivers of affected children aged 1–7 years) and six dermatology experts who were not involved in scale development indicated that all of these domains except epidermal function are important from the patients’ and clinical experts’ perspectives (Schmitt et al., 2007). Additional domains considered as potentially relevant for the core set were general and dermatology-specific quality of life, control of disease flares, health utilities, work/school limitations, consequences of pruritus, cost effectiveness, direct/indirect cost, and compliance.

It was specified that scores of 1–3 represent a region where participants believe the domain is not important; 4–6 a region of equivocal value; and 7–9 a region where they feel the domain is important (Jones and Hunter, 1995). In the first round of the Delphi exercise, participants were asked to list additional outcome domains they considered as potentially relevant. Additionally, they were asked in the first round to indicate how many domains should be included in the final core set of outcome domains for each context. In subsequent rounds, participants received feedback on their own response along with the group opinion for each domain (median and interquartile range, calculated using Stata 10, Stata, College Station, TX) from the previous round. (Figure 3) Respondents could submit new scores or leave their scores unchanged. Three rounds were conducted by electronic mail or facsimile. In the final round, instead of ranking the importance of the individual domains on a Likert scale, participants were asked explicitly which domains they recommend incorporating into the core set. It was specified that outcomes included in the core set for eczema trials ‘‘should be assessed routinely in every clinical trial, but not necessarily as a primary outcome’’ and that those outcomes included into the core set for clinical recordkeeping ‘‘should be assessed routinely at every patient visit in routine practice’’.

Definition of consensus:
A priori consensus was defined as being achieved if at least 60% of all members of at least three stakeholder groups including consumers recommended including a domain in the core set of outcomes.Consensus that an outcome is important for eczema was defined as a score of 7 or more (as described above, a score of 7–9 indicated that the participating experts felt that a certain domain was important to include) by at least 60% of all members of at least three stakeholder groups including consumers (Loughlin and Moore, 1979; Hasson et al., 2000).

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