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

Abstract

Summary Peripheral vascular malformations (VMs) are birthmarks or swellings caused by the faulty development of blood vessels in the embryo. Different types are classified according to whether the components are mainly lymph vessels (LMs), veins (VMs) or combined arteries and veins (AVMs). It is hard to assess the various medical and surgical treatments available because there are no agreed methods for measuring the outcome. This international group carried out an on‐line survey of health professionals and patients to decide which factors would be important to record in future clinical trials. First they listed aspects of the condition and its treatment in 36 domains covering 97 specific items. Then they asked 167 doctors and 134 patients and parents of patients to score the domains from 0 (not important) to 4 (crucial). The options were progressively narrowed down over 3 rounds of the survey and a consensus conference. The finally agreed “core outcome set” covered: scan results, doctors’ assessment of problems caused by pressure from the VM, patient or parent's assessments of symptoms, pain and quality of life, and their satisfaction with the treatment, outcome and any adverse effects. Additional specific factors for LMs were infections and lymphatic fluid leakage, for VMs thrombosis and for AVMs heart function and bleeding. Recurrence after treatment and appearance were also recommended for inclusion. This international consensus establishes what factors should be assessed in future trials of treatments for vascular malformations, but further work is required to decide exactly how they should be measured and reported.

Methodology in core outcome set (COS) development: the impact of patient interviews and using a 5-point versus a 9-point Delphi rating scale on core outcome selection in a COS development study.

“…The 9-point scale is recommended by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group to assess the importance of evidence and is the scale used in DelphiManager, a web-based system designed by the COMET Initiative for facilitating and managing Delphi surveys [2,21,22]. The 5-point rating scale was arbitrarily chosen as the comparator scale because it had been used previously in COS development Delphi studies [23][24][25], and because 5-point rating scales are relatively common across research studies that include a rating scale. Participants used the same rating scale they were initially allocated for all three Delphi rounds.…”

By using a core outcome set we measure what matters to patients

“…For example, in a systematic review of the literature in atopic eczema, the authors found substantial heterogeneity in outcome measurement instruments used to measure disease severity . In vitiligo, similar variability in outcome reporting was found, and this is also the case for other dermatological diseases such as acne, hidradenitis suppurativa, psoriasis and vascular malformations …”

“…5 In vitiligo, similar variability in outcome reporting was found, 6 and this is also the case for other dermatological diseases such as acne, 7 hidradenitis suppurativa, 8 psoriasis 9 and vascular malformations. 10 Using incomparable outcomes is considered a waste of valuable healthcare resources and is unwanted. 11 Moreover, for the majority of dermatological diseases, we do not know which outcomes are considered most important to patients and their healthcare providers.…”

Long‐term health‐related quality of life in children with lymphatic malformations treated with sclerotherapy generally matched age‐appropriate standardised population norms

“…It has become an increasingly important outcome measure from a clinical and epidemiological point of view . An international multicentre consensus study, the Outcome Measures for Vascular Malformations project, suggested core outcome sets for clinical research on peripheral vascular malformations, including lymphatic malformations, venous malformations and arteriovenous malformations . It agreed that HRQoL should be a core outcome measure for all types of vascular malformations.…”