Interrater Reliability for Classifying Craniofacial Microsomia Severity: A Call for Objective Evaluation

Objective: The severity of craniofacial microsomia (CFM) is generally classified using the Orbit, Mandible, Ear, Soft tissue, Nerve (OMENS) classification score. The global assessment of the Phenotypic Assessment Tool for Craniofacial Microsomia (PAT-CFM), is a pictorial modification of the OMENS classification. The aim of this study was to assess the interrater reliability of the PATCFM global assessment score. Design: In this prospective cohort study, three clinicians completed the global assessment form of the PAT-CFM. The mandible was classified based on orthopantomogram- and/or computed tomography images. Participants: Consecutive patients with CFM or microtia. Main Outcome Measure: Interrater agreement was calculated using the weighted Krippendorff alpha (alpha), with 95% confidence intervals (CI). Results: In total, 53 patients were included (106 hemifaces). The reliabilities of the main classification components ranged from high for the mandible (alpha= 0.904 [95% CI 0.860-0.948]) and ear (alpha = 0.958 [95% CI 0.934-0.983]) subscales, to tentative for the orbital summary score (alpha= 0.682 [0.542-0.821]), and nerve summary score (alpha= 0.782 [0.666-0.900]) subscales. Conclusions: The reliability of the ear and radiographic mandible scales of the PAT-CFM global classification were high, while the orbit, facial nerve and soft tissue subscales may have limited reliability. Research focusing on radiographic severity scores for hypoplasia of the orbits and soft tissues, as well as objective measures for overall facial hypoplasia using non-ionizing forms of imaging for early classification, are warranted.