Subjective health perception prioritizes psychological well-being over physical function in advanced ALS: A multigroup structural equation modeling analysis

Background: Despite declining physical function, individuals with ALS report relative preservation of overall health perception, or health-related quality of life (HRQoL). This paradoxical finding is attributed to psychological adaptation to deficits.

Objective: The aim of this cross-sectional study was to examine reprioritization of factors that determine HRQoL with disease progression.

Methods: As standard care, patients with ALS self-reported ALSFRS-R (measure of bulbar, motor, and respiratory function), PHQ-9 (measure of depression), and EQ-5D-3L (utility index that includes a visual analog scale asking about health perception [EQ-VAS]). ALS was staged by the FT9 method and classified into early (stages 0-2) and late (stages 3-4) disease. Multigroup structural equation modeling was used to evaluate weights of physical (PHY) and psychological well-being (PSY) for early and late disease, on EQ-VAS (as a measure of overall HRQoL).

Results: There were 578 patients (mean age 61.5 ± 11.9, 59% male) with ALS: 423 (73%) early and 155 (27%) late disease. A measurement model was established with good model fit (RMSEA = 0.076, CFI = 0.943, SRMR = 0.045). In adjusted models, standardized weights of PHY and PSY on HRQoL in early disease were 0.34 (standard error = 0.06) and 0.24 (0.06) respectively, whereas for late disease they were 0.39 (0.07) and 0.42 (0.07). Importantly, PHY and PSY were significantly correlated in early but not in late disease.

Conclusions: Our study found health perception is more representative of psychological well-being and less representative of physical function across the disease progression. Greater allocation for psychological health would be the most effective strategy to maximize subjective health status as ALS advances.