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

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