AIMS. This study was conducted with the aim of developing the Spanish version of the Hammersmith functional rating scale for children with spinal muscular atrophy (SMA), to establish the interobserver reliability and to adapt it to Spanish children with SMA types II and III.

PATIENTS AND METHODS We assessed 31 children with a mean age of 4.7 years (range: 2.5-9 years) and they were re-assessed at 3, 6 and 12 months. The children with SMA type II could not walk and the children with SMA type III were able to walk.

RESULTS Interobserver reliability was 95%. The median of the score in the group with SMA type II was 17 (range: 0-34) and in the SMA type III group it was 39 (range: 37-40). The results of the group with SMA type II at 12 months were poorer, although not to a statistically significant extent, which suggested that the disease was getting worse.

CONCLUSIONS The Spanish version presents a high degree of interobserver reliability, is easy to administer in clinical practice and is a good tool for assessing the severity of the disease in patients with SMA, above all in those who are unable to walk.

Objetivos Desarrollar la versión española de la escala de valoración funcional de Hammersmith para niños con atrofia muscular espinal (AME), establecer la fiabilidad interobservador y adaptarla a niños españoles con AME tipos II y III.

Pacientes y métodos Evaluamos 31 niños con una edad media de 4,7 años (rango: 2,5-9 años), y los reevaluamos a los 3, 6 y 12 meses. Los niños con AME tipo II no caminaban y los niños con AME tipo III eran ambulantes.

Resultados La fiabilidad interobservador era del 95%. La mediana de la puntuación en el grupo con AME II era de 17 (rango: 0-34), y en el grupo con AME III, de 39 (rango: 37-40). Los resultados del grupo con AME II a los 12 meses disminuían, aunque sin significancia estadística, lo que sugería empeoramiento de la enfermedad.

Conclusiones La versión española presenta gran fiabilidad interobservador, fácil administración en la práctica clínica y es una buena herramienta para evaluar la gravedad de la enfermedad en pacientes con AME, principalmente no ambulantes.