The Amyotrophic Lateral Sclerosis Functional Rating Scale Predicts Survival Time in Amyotrophic Lateral Sclerosis Patients on Invasive Mechanical Ventilation

Objective:To determine whether the amyotrophic lateral sclerosis functional rating scale (ALSFRS), which is a validated instrument that assesses the functional status and the disease progression in patients with amyotrophic lateral sclerosis (ALS), predicts hospital length of stay and survival time in ALS patients treated with tracheostomy-intermittent positive-pressure ventilation (TIPPV).Methods:Thirty-three consecutive ALS patients with acute respiratory failure who received therapy with TIPPV were prospectively followed up from their admission to the hospital until death. The association of ALSFRS score at hospital admission with length of hospital stay and survival after TIPPV were examined using Cox proportional hazard models, adjusting for age at baseline, sex, and symptom duration.Results:The median ALSFRS score of the ALS patients at hospital admission was 11 (range, 4 to 22). The median length of hospital stay was 55 days (range, 7 to 124 days), with a hospital mortality rate of 9%. For the 30 patients (91%) discharged from the hospital, the median survival time was 37 months (range, 2 to 64 months). The total ALSFRS score (above or below the median score) was a significant predictor of length of hospital stay (hazard ratio [HR], 2.86; 95% confidence interval [CI], 1.2 to 6.5; p = 0.003) and survival after TIPPV (HR, 3.76; 95% CI, 1.4 to 9.7; p = 0.002). The total ALSFRS score at hospital admission was also associated with length of hospital stay (HR, 2.1; 95% CI, 1.1 to 5.1; p = 0.005) and survival (HR, 0.52; 95% CI, 0.1 to 0.8; p = 0.002) when included in a Cox multivariable model together with the other demographic and clinical variables.Conclusion:In ALS patients with acute respiratory failure who have been treated with TIPPV, the total ALSFRS score may predict length of hospital stay and long-term survival after invasive mechanical ventilation.