Describe properties of an array of Likert-based health-related quality-of-life measurements compared with the McGill University Single Item Quality-of-Life ( QoL ) scale.

Currently ALS specific quality-of-life clinimetric scales do not have specific questions related to breathing.  Respiratory function is one of the main determinants of survival in ALS patients

ALS-MDA Care Center population in MDA ALS Outcomes Registry of 106 ALS patients at first diagnosis was evaluated with ALS Functional Rating Scale–Revised (ALSFRSR), McGill SIQoL, and additional health-related quality-of-life scales related to (1) energy, (2) getting about the community, (3) walking, (4) sit to stand, (5) toileting,(6) feeding, (7) swallowing, (8) communication (9) secretions, (10) breathing, (11) pain, (12) anxiety, (13) home care equipment provision.  Each scale was rated by the patient from 0–10 employing integral scores. 

McGill SIQoL is driven by anxiety QoL ( McGill Overall SIQoL  / Anxiety  Spearman rho = 0.739 [ 95 % CI = 0.526-0.865 ] P < 0.0001 ).  McGill SIQoL is driven by less by breathing  QoL  ( McGill SIQoL Overall / Breathing  Spearman    rho = 0.521 [ 95 % CI = 0.210-0.736 ] P = 0.0022 ).  McGill SIQoL is not driven by communication QoL ( McGill SIQoL Overall / Communication Spearman rho = 0.120 [ 95 % CI = -0.239 to 0.450 ] P = 0.5145 ). Breathing QoL is driven more by dyspnea self report than ALSFRSR orthopnea item score ( Breathing QoL / ALSFRSR orthopnea rho = 0.485 [ 95 % CI = 0.164-0.713] P = 0.0049) or ALSFRSR respiratory item score ( Breathing QoL / ALSFRSR respiratory  rho = 0.506 [ 95 % CI = 0.191-0.726 ] P = 0.0031).

Overall QoL measured by McGill SIQoL is impacted most by the anxiety QoL and feeding QoL domains with breathing QoL ranked sixth among the domains measured. Breathing QoL is impacted most by the  ALSFRSR dyspnea item score compared with the ALSFRSR orthopnea and respiratory item scores.