Hemangioma Activity and Severity Index (HASI), an instrument for evaluating infantile hemangioma: development and preliminary validation.

Background: Infantile hemangiomas (IHs) are the most common benign vascular tumors of infancy. Their evaluation is important and requires the use of a unified scoring system.

Objectives: We designed a novel scoring index, the Hemangioma Activity and Severity Index (HASI), for the clinical evaluation of IHs. The purpose of this pilot study was to validate the HASI.

Methods: The HASI was evaluated for validity by an external panel of experts. The reliability study included 59 children with superficial and mixed hemangiomas. Patients attended an assessment visit and a subsequent visit three days later for a second scoring. They were then followed up monthly for six months and scored at each visit by two investigators separately.

Results: Interclass correlation coefficients (ICCs) for inter-rater reliability were 0.82 (95% confidence interval [CI] 0.75-0.88) for IH activity and 0.94 (95% CI 0.91-0.96) for IH severity. Intra-rater reliability was high, with negligible mean differences of 0.3 and 0.4 points between the two ratings. The average time required to complete the scoring was 2.5 minutes.

Conclusions: Our preliminary studies on the HASI show promising results in terms of its clinical utility and applicability in practice. It could be used by physicians as an objective instrument for the scoring of IHs.