Core Outcome Set for Actinic Keratosis Clinical Trials

Although various treatments have been found in clinical trials to be effective in treating actinic keratosis (AK), researchers often report different outcomes. Heterogeneous outcome reporting precludes the comparison of results across studies and impedes the synthesis of treatment effectiveness in systematic reviews.

To establish an international core outcome set for all clinical studies on AK treatment using systematic literature review and a Delphi consensus process.

Survey study with a formal consensus process. The keywords actinic keratosis and treatment were searched in PubMed, Embase, CINAHL, and the Cochrane Library to identify English-language studies investigating AK treatments published between January 1, 1980, and July 13, 2015. Physician and patient stakeholders were nominated to participate in Delphi surveys by the Measurement of Priority Outcome Variables in Dermatologic Surgery Steering Committee members. All participants from the first round were invited to participate in the second round. Outcomes reported in randomized controlled clinical trials on AK treatment were rated via web-based e-Delphi consensus surveys. Stakeholders were asked to assess the relative importance of each outcome in 2 Delphi survey rounds. Outcomes were provisionally included, pending the final consensus conference, if at least 70% of patient or physician stakeholders rated the outcome as critically important in 1 or both Delphi rounds and the outcome received a mean score of 7.5 from either stakeholder group. Data analysis was performed from November 5, 2018, to February 27, 2019.

A total of 516 outcomes were identified by reviewing the literature and surveying key stakeholder groups. After deduplication and combination of similar outcomes, 137 of the 516 outcomes were included in the Delphi surveys. Twenty-one physicians and 12 patients participated in round 1 of the eDelphi survey, with 17 physicians (81%) retained and 12 patients (100%) retained in round 2. Of the 137 candidate outcomes, 9 met a priori Delphi consensus criteria, and 6 were included in the final outcomes set after a consensus meeting: complete clearance of AKs, percentage of AKs cleared, severity of adverse events, patient perspective on effectiveness, patient-reported future treatment preference, and recurrence rate. It was recommended that treatment response be assessed at 2 to 4 months and recurrence at 6 to 12 months, with the AK rate of progression to cutaneous squamous cell carcinoma reported whenever long-term follow-up was possible.

Consensus was reached regarding a core outcome set for AK trials. Further research may help determine the specific outcome measures used to assess each of these outcomes.