Correspondence to Dr Murad Alam; [email protected]
Strengths and limitations of this study
The Delphi method allows us to recruit a multitude of globally diverse physicians, patients and stakeholders, which ensures the incorporation of distinct perspectives and assures the results have a heightened impact.
The Delphi method is an accurate tool for consensus, as it allows for participant feedback to be provided in an anonymous way, permitting individuals to freely express their opinions.
While the study will identify core outcomes for acne scarring, it will not determine which measurement tools can be used to assess these outcomes.
Although the study aims for global diversity, the study may be limited by the demographics of involved participants, as some regions may have higher representation than others.
Introduction
Scarring is one of the primary sequelae that affect patients with acne. In fact, facial scarring occurs to some extent in 95% of patients with active acne, regardless of sex.1 Acne scars are the result of inflammation of acne blemishes. These blemishes often form when skin pores become clogged with bacteria, excess oil and dead skin cells.2 Acne scarring has been divided into three different subtypes: atrophic, hypertrophic and keloid types. Active acne lesions may undergo dysregulated collagen production leading to scarring. A net gain or loss of collagen during the remodelling process determines whether the scar is hypertrophic or atrophic, respectively.3 Acne generally starts in adolescence and often resolves by mid-20s. It peaks between the ages of 14–19 years with a prevalence of approximately 95%.4 Acne scarring has a large impact on self-esteem, overall quality of life and body image. It has been shown to perpetuate maladaptive thought processes established during active acne.5 Acne scarring can affect patients’ psychological state and their physical appearance, and as no universally accepted treatment guidelines exist, this is an important topic of research. There are several therapeutic approaches that exist to reduce the appearance of acne scars including topical retinoids, chemical peels, facial resurfacing techniques (e.g., dermabrasion and microdermabrasion), laser treatments, subcision, dermal grafting, skin needling, topical treatments (eg, silicone gel), steroid therapy and surgery.6–10
Although some Cochrane reviews have investigated the effectiveness of these therapeutic interventions, heterogeneity in reporting clinical outcomes across trials still exists.11 The lack of standardisation of outcome assessment across trials makes it challenging to adequately compare the efficacy of various treatments. Core Outcome Measures in Effectiveness Trials Initiative (COMET), an organisation formed to address this issue, is dedicated to establishing universal core outcome sets (COSs) in different health-related domains.12 A COS is defined as a minimum set of outcomes that should be measured and reported in all clinical trials for a given health condition.13 The CHORD COUSIN Collaboration (C3) is a global research organisation with the primary goal of developing, disseminating and implementing high quality COSs for trials and clinical research in dermatology. C3 works to improve the health of patients by evaluating interventions for skin conditions.14 There are various COSs being formulated to address different dermatologic conditions; however, on searching the COMET database, a COS specific to acne scarring has not been developed.15
Objectives
The primary objective of this study is to develop a COS for clinical trials evaluating acne scarring interventions. We aim to identify a long list of potential outcomes through a systematic review, stakeholder and patient input and review of grey literature, including patient brochures, pamphlets, clinical trial registries and other sources of documentation. This list will then be refined by steering committee members before undergoing an e-Delphi survey, involving international experts in the field and consensus meetings. Finally, we aim to achieve consensus on a set of core outcomes that can be used for all clinical trials of acne scarring.
We have developed this protocol based on recommendations from the Core Outcome Set-STAndardised Protocol Items (COS-STAP) Statement.16
Scope of this COS
Health condition
Acne scarring.
Population
All individuals with acne scarring.
Types of interventions
All treatment interventions for acne scarring including, but not limited to, topical treatments, facial resurfacing techniques, laser and energy-based devices, grafting and surgery options and steroid therapy.
Setting
This COS is intended for use in clinical trials measuring the efficacy of acne scarring interventions.
Methods
The COS will be developed according to the COMET handbook.17 Figure 1 outlines our study design.
Stakeholders
We aim to assemble a globally diverse group of stakeholders comprised of clinicians, patients, researchers and individuals from industry and research organisations. Criteria for selection will include: (1) senior or first authors who have produced a peer-reviewed and published article on acne scarring from 2018 to 2023; or (2) board members from national and international organisations that have a focus on acne scarring research and treatments; or (3) peer nomination as an expert in acne scarring by at least two individuals from categories (1) or (2). Physicians participating in the Delphi process may nominate patients with acne scarring to participate in the patient Delphi group. To ensure international participation and diversity, we will recruit physicians and patients of different ethnicities from major continents (North America, South America, Asia, Africa, Europe and Australia), as well as major geographic regions within these (e.g., for Asia we will have members from the near east/middle east, as well as from East Asia). We will recruit participants from highly developed economies as well as lower middle-income countries (LMIC) and upper middle-income countries (UMIC). All participants in the Delphi process will be required to disclose all relevant conflicts of interest and relationships with industry, which will be documented. At least 51% of participants in either of the stakeholder groups must not have relevant conflicts. In addition, participants with relevant conflicts may not chair the subcommittees or workgroups in their area of conflict. The steering committee, which will develop the COS using the outcomes obtained, will include six physicians: MA (Northwestern University), IAM (University of Minnesota), JFS (University of Pennsylvania), TVC (Pennsylvania State University) and two additional non-US based physician experts. Additionally, there will be an independent member of the CS-COUSIN Methods Group, JJK, who will provide methodological recommendations for the COS development. We will also have at least two patient representatives, who have acne scarring, on the steering committee to better represent the patient perspective and to help reword lay definitions for patient participants.
Information sources
Outcomes will be obtained from four sources. First, a systematic literature review of English-language human randomised controlled trials (RCTs) of acne scarring will be conducted to identify measured outcomes. The systematic review has been registered with the International Prospective Register of Systematic Reviews (CRD42023460964) and will be conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement.18 Two independent reviewers will search PubMed/Medline and Embase from 2013 to 2023 to detect RCTs including the following terms [(acne AND cicatrix (All Fields)) AND (RCT (publication type)) AND (treatment OR therapy OR therapeutics OR management OR intervention (All Fields)) AND (surgery OR procedure (All Fields)) AND (topical OR oral OR injectable OR biologics OR lasers OR resurfacing (All Fields))]. Studies will be included if: (1) they are randomised and controlled; (2) assess the efficacy of interventions for the treatment of acne scarring; (3) are available in the English language; (4) involve solely human subjects; (5) they were published between 2013–2023. Studies will be excluded if: (1) they are published as a poster or conference abstract; (2) the full text is not available. The same two investigators will independently screen articles for eligibility, with disagreements resolved by a third investigator. Study characteristics, including title, authors, journal of publication and publication date, will be recorded. The two reviewers will then independently extract study outcomes, with similar outcomes only being listed once. Second, patients with acne scarring will be asked to determine outcomes through semistructured interviews. Clinicians participating in the two rounds of Delphi will be asked to nominate patients for the study. Third, printed and electronic sources with information on acne scarring and acne scarring treatments will be reviewed for additional outcomes. Finally, healthcare providers will participate in semistructured interviews to elicit other potential outcomes not previously recorded. Outcomes from these four sources will be compiled into a provisional long list of outcomes. We will also review the core outcomes arrived at the ACORN group, which studied core outcomes for active acne, to inform our work and reach out to the leadership of the ACORN group for additional information as necessary. The steering committee will then revise this long list of outcomes by adding additional outcomes deemed necessary, omitting duplicates and rewording definitions for clarity. The steering committee will then use the COMET taxonomies to categorise the long list of outcomes into domains.19 A two-stage Delphi survey process will then be conducted.
Consensus process
The data extracted from the information sources will inform a two-stage Delphi consensus process. On conclusion of both Delphi rounds, a virtual consensus meeting will be held to determine the final core set of outcomes. Physicians and patients who participated in the Delphi will be invited to discuss the results of the Delphi rounds, including the provisional outcomes and outcomes for which consensus was not reached. The consensus meeting will be held in an open-discussion format with a facilitator moderating the meeting. Participant scores from the final Delphi round will be shown when discussing each outcome. Several consensus meetings may be necessary to accommodate different time zones and schedules. Participants will be sent poll surveys with three different dates and times for virtual consensus meetings. Each meeting should have balanced geographic representation and patient participants. During the meetings, participants will vote to include or exclude outcomes in the final COS using live polling software. The results of the different consensus meetings will be harmonised by members of the steering committee. In particular, any changes recommended in at least two consensus meetings will always be adopted. The harmonised results will then be reviewed by all participants via an email ballot. On conclusion of the consensus meeting(s), a COS that is agreed on by all participants should result.
Consensus definition
Provisional consensus for inclusion will apply to items if 70% of all stakeholder groups rank an outcome 7, 8 or 9, with less than 15% ranking it 1, 2 or 3. Outcomes will not be considered for provisional consensus if 70% or more of the groups score 1–3 and less than 15% score 7–9. Outcomes that do not meet the inclusion criteria after the second round will not be included.
Outcome scoring/feedback
Participants will rank outcomes on a 9-point Likert scale devised by the Grading of Recommendations Assessment, Development and Evaluation working group.20 A score of 9 indicates that the outcome is ‘critically important’ to include in the COS, while a score of 1 would signify that the outcome is ‘not important at all’. Ratings falling between 1–3 will be categorised as having a lack of importance, scores of 4–6 would indicate an uncertain degree of importance and scores of 7–9 would signify importance. Participants will also have the option to select ‘unable to score’, if they feel they are unable to assess a particular outcome. Participants may propose additional outcomes to be included in the COS. In the second round of Delphi, participants will be presented with the outcomes included in the initial round, along with their ratings of each outcome and the average ratings provided by participants in that round. They will have the option to modify their initial rating based on this information.
Missing data
Participants who do not participate in the first round of Delphi will not be invited to the second round.
Patient and public involvement
The perspectives of patients and the public will be incorporated throughout this study. Specifically, patient stakeholders will participate in the two-round Delphi study, where they will be asked to rate outcomes. They will also be provided with plain-language definitions of the outcomes. Additionally, a minimum of two patient representatives will be included in the steering committee, as mentioned above. Finally, patient feedback will be elicited during the semistructured interviews and at the consensus meetings to ensure that patient-centred outcomes are incorporated. Patient stakeholders that consent to being named as contributors will be included in any published work that arises from the study.
Ethics
Ethics and informed consent
Ethical approval and consent to participate for the study has been granted by Northwestern University Institutional Review Board (IRB) protocol ID: STU00097285. This study is registered with COMET and C3.
Dissemination
Upon completion of the COS, we plan to publish our results in peer-reviewed journals and communicate our findings at conference presentations. All participants will be sent the results of the study and encouraged to adopt the COS in clinical practice.
Discussion
Currently, there is no COS relevant to clinical trials for acne scarring. Through incorporation of opinions of physicians, patients and other key stakeholders, we intend to develop a COS to reduce outcome heterogeneity in clinical practice and research. The COS will suggest a standard collection of outcomes that should be measured when evaluating treatments for acne scarring. This is necessary to effectively compare and assess various treatment approaches, address the lack of standardisation in the assessment of outcomes and attenuate potential reporting biases. The utilisation of a COS in future trials and clinical practice would allow for more conclusive evaluations regarding the advantages of available treatments.
The Delphi method, which this study will use to gain consensus, has several strengths. This method allows us to recruit a multitude of globally diverse physicians, patients and stakeholders. The variety of expertise and background of the participants ensures the incorporation of distinct perspectives and assures the results have a heightened impact. Additionally, the Delphi method is an accurate tool for consensus, as it allows for participant feedback to be provided in an anonymous way, permitting individuals to freely express their opinions. Consensus is a prime component of the Delphi method; however, advanced declared protocols do not always provide the process of achieving consensus, as consensus can signify a group opinion, solidarity towards a sentiment or absolute alignment of expert opinion.21 We aim to address this issue by creating a predefined cut-off of 70% consensus among Delphi participants. Finally, this COS will establish what outcomes should be measured in relation to acne scarring; however, it will not provide a way to measure these outcomes. We hope to develop a core outcome measure set for acne scarring in the future to address this limitation.
Ethics statements
Patient consent for publication
Not applicable.
Contributors The study concept and design was conceived by MA, JFS, TVC, JJK and IAM. MH has led the development of the protocol and drafted the initial manuscript. The manuscript has been critically reviewed and revised by EK, JJK MSM, AA, VJS and BC. Administrative, technical or material support was provided by MH, EK, MSM, AA, VJS and BC. MA is the guarantor.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient and public involvement Patients and/or the public were involved in the design, conduct, reporting or dissemination plans of this research. Refer to the Methods section for further details.
Provenance and peer review Not commissioned; externally peer reviewed.
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Details
; Maher, Ian A 4 ; Sobanko, Joseph F 5 ; Cartee, Todd V 6 ; Alam, Murad 7
1 Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
2 Department of Dermatology, University of Illinois Chicago, Chicago, Illinois, USA
3 Centre for Biostatistics, The University of Manchester, Manchester, UK
4 Department of Dermatology, University of Minnesota, Minneapolis, Minnesota, USA
5 Department of Dermatology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
6 Penn State Health Milton S Hershey Medical Center, Hershey, Pennsylvania, USA
7 Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA; Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA; Department of Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA