Development of an international core outcome set for peripheral vascular malformations: the OVAMA project

Summary

Background

An important limitation in vascular malformation research is the heterogeneity in outcome measures used for the evaluation of treatment outcome.

Objectives

To reach international consensus on a core outcome set (COS) for clinical research on peripheral vascular malformations: lymphatic (LM), venous (VM) and arteriovenous malformations (AVM). In this consensus study, we determined what domains should constitute the COS.

Methods

Thirty‐six possibly relevant outcome domains were proposed to an international group of physicians, patients and the parents of patients. In a three‐round e‐Delphi process using online surveys, participants repeatedly rated the importance of these domains on a five‐point Likert scale. Participants could also propose other relevant domains. This process was performed for LM, VM and AVM separately. Consensus was predefined as 80% agreement on the importance of a domain among both the physician group and the patient/parent group. Outcomes were then re‐evaluated in an online consensus meeting.

Results

167 physicians and 134 patients and parents of patients with LM (n = 50), VM (n = 71) and AVM (n = 29) participated in the study. After three rounds and a consensus meeting, consensus was reached for all three types of vascular malformations on the core domains of radiological assessment, physician‐reported location‐specific signs, patient‐reported severity of symptoms, pain, quality of life, satisfaction and adverse events. Vascular malformation type‐specific signs and symptoms were included for LM, VM and AVM, separately.

Conclusions

Our recommendation is that therapeutic‐efficacy studies on peripheral vascular malformations should measure at least these core outcome domains.