Development and Preliminary Validation of the Patient-Reported Outcome Measure for Vascular Malformation Questionnaire: A Prospective Cohort Study

Purpose: To develop and validate the Patient-Reported Outcome Measure for Vascular Malformation (PROVAM) questionnaire to assess the health-related quality of life in patients with vascular malformations. Materials and Methods: We developed and validated PROVAM using a mixed methods design during a prospective clinical trial at a vascular anomalies clinic. From July 2019 to February 2020, 108 consecutive patients completed 130 questionnaires. The 30-item instrument assessed the domains of pain, emotional/social well-being, functional impact, and treatment satisfaction. Two additional items assessed ease of understanding and relevance. The primary outcomes of instrument reliability and validity were evaluated across several indices. The secondary outcome of responsiveness evaluated total score changes for patients who completed questionnaires both before and after treatment. Results: Instrument reliability, as measured by Cronbach alpha, was >= 0.79 for pain, emotional/social well-being, and functional impact domains. Primary domain structure was confirmed by factor analysis (P <. 001) and convergent construct validity for all but 1 Likert scale item. In the subgroup analysis of 13 participants who completed PROVAM before and after treatment, instrument responsiveness, as measured by the total score, showed a significant decrease (median, similar to 10 points; interquartile range [IQR], -3 to -16; P = .04). Participants found the questions easy to understand (median, 5 points; IQR, 4-5 on a 5-point scale) and relevant (median score, 4; IQR, 3-5). Conclusions: Preliminary data support the reliability and validity of PROVAM in measuring the health-related quality of life in patients with vascular malformations.