TTR and susceptibility to pneumonia measurement: After investigating the prevalence and risk factors of SRS in hospitalized patients receiving rehabilitation treatment, it was found that, compared to the patients without SRS, the patients with SRS were significantly older, less weighed, and had significantly (p < 0.05) decreased levels of albumin, RAG, creatinine, uric acid, red blood cell count, hemoglobin, prealbumin, iron, creatine kinase, college education or above, and walking ability besides significantly longer ICU stay, history of pneumonia, cognitive impairment, aphasia, and nasogastric feeding.