INTRODUCTION: The Amyotrophic Lateral Sclerosis (ALS)-Specific Quality of Life instrument and its revised version (ALSSQOL and ALSSQOL-R) have strong psychometric properties, and have demonstrated research and clinical utility. In this study we aimed to develop a short form (ALSSQOL-SF) suitable for limited clinic time and patient stamina.

METHODS: The ALSSQOL-SF was created using Item Response Theory and confirmatory factor analysis on 389 patients. A cross-validation sample of 162 patients assessed convergent, divergent, and construct validity of the ALSSQOL-SF compared with psychosocial and physical functioning measures.

RESULTS: The ALSSQOL-SF consisted of 20 items. Compared with the ALSSQOL-R, optimal precision was retained, and completion time was reduced from 15-25 minutes to 2-4 minutes. Psychometric properties for the ALSSQOL-SF and its subscales were strong.

DISCUSSION: The ALSSQOL-SF is a disease-specific global QOL instrument that has a short administration time suitable for clinical use, and can provide clinically useful, valid information about persons with ALS. Muscle Nerve 58: 646-654, 2018.