# Classification of central facial paralysis: an agreement analysis

## TL;DR

This study compares two scales for classifying central facial paralysis and finds that the Sunnybrook Facial Grading System is preferred by experts for its better interrater agreement.

## Contribution

The study evaluates and compares the reliability of two facial paralysis classification scales using expert assessments.

## Key findings

- The HB scale showed considerable interrater and excellent intrarater agreement.
- The SFGS had good interrater and intrarater agreement and was preferred by all experts.
- Both scales are useful, but the SFGS is considered more appropriate for classifying central facial paralysis.

## Abstract

To identify whether there is interrater and intrarater agreement in the classification of the degree of central facial paralysis using two scales and verify which one is more appropriate to classify the severity of facial expressions according to experts’ opinion.

Observational, prospective, cross-sectional study of agreement analysis of the House & Brackmann (HB) scale and the Sunnybrook Facial Grading System (SFGS). Five speech-language-hearing pathologists with clinical experience analyzed post-stroke facial expression of 30 adults for interrater agreement. They were evaluated in two stages, with a 10-day interval; the second stage involved 20% ​​of the initial sample for intrarater agreement. The study used weighted kappa coefficient for the HB scale and the intraclass correlation coefficient for the SFGS classification.

The HB scale indicated considerable interrater and excellent intrarater agreements. The SFGS had good interrater and intrarater agreements. All speech-language-hearing pathologists considered the SFGS the most appropriate scale for classifying central facial paralysis.

The SFGS performed better in interrater agreement analysis. The HB scale had considerable merits in the intrarater assessment. Both scales are adaptable and useful to assess and classify central facial paralysis. However, the speech-language-hearing pathologists indicated the SFGS as the most appropriate.

Identificar se há concordância inter e intra-avaliadores na classificação do grau de paralisia facial central por meio de duas escalas, e qual delas é mais adequada para classificar a gravidade da mímica facial de acordo com a opinião de especialistas.

Estudo observacional, prospectivo de corte transversal de análise de concordância das escalas de House & Brackmann (HB) e do Sistema de Graduação Facial Sunnybrook (SFGS), realizado com cinco fonoaudiólogos com experiência clínica que analisaram a expressão facial de 30 indivíduos adultos após Acidente Vascular Cerebral para concordância interavaliadores. As avaliações foram realizadas em duas etapas, com 10 dias de intervalo, sendo a segunda etapa com 20% da amostra inicial para concordância intra-avaliadores. Foi empregado o coeficiente kappa ponderado para a escala HB e o coeficiente de correlação intraclasse ICC para a classificação SFGS.

A escala HB indicou concordâncias interavaliadores considerável e intra-avaliadores excelente. O SFGS apresentou boa concordância interavaliadores e intra-avaliadores. Todos os fonoaudiólogos consideraram o SFGS como a escala mais adequada para classificação da paralisia facial central.

O SFGS demonstrou desempenho superior na análise da concordância interavaliadores. A escala HB evidenciou méritos consideráveis na avaliação intra-avaliadores. Ambas as escalas estão aptas a serem adaptadas e utilizadas na avaliação e classificação da paralisia facial central, contudo, os fonoaudiólogos indicaram a SFGS como a mais adequada.