METHODS: The Adelphi ALS Disease Specific Programme (DSP™) is a point-in-time survey of neurologists and their ALS patients and caregivers in France, Germany, Italy, Spain, the UK, and the USA (Jul 2020–Mar 2021). Neurologists completed questionnaires on their consulting patients’ demographics and clinical characteristics, including King’s and MiToS staging. These ALS patients (and caregivers, if applicable) were invited to complete questionnaires focused on disease burden and HRQoL measures, including the EQ-5D-5L. Correlation of crosswalk EQ-5D index scores (UK tariffs) with King’s and MiToS stages was assessed through linear regression; adjusted for age, sex, BMI, and number of comorbidities.

RESULTS: 142 neurologists reported data on 880 ALS patients; complete EQ-5D-5L data were provided by 163 patients (or caregiver proxy). EQ-5D index scores were significantly negatively correlated with both King’s (Stage 1: 0.635; Stage 2: 0.512; Stage 3: 0.469; Stage 4: 0.158; r₂= 0.318, p<0.001), and MiToS stage (Stage 0: 0.547; Stage 1: 0.318; Stage 2: 0.045; Stage 3: 0.039; Stage 4: -0.085; r₂= 0.461, p<0.001).

CONCLUSIONS: HRQoL showed substantial declines at certain stages (King’s Stage 4; MiToS Stage 2), with EQ-5D index scores in late stages relating to a HRQoL close to or worse than death. For MiToS, where complete loss of function in a domain is required to progress to the subsequent stage, a steeper HRQoL decline across stages was demonstrated than for King’s. The results demonstrate the impact of disease progression, as assessed by two independent staging systems, on HRQoL and the benefit of keeping patients at earlier stages for longer.