Relationship between daily swallowing frequency and pneumonia in patients with severe cerebral palsy

BACKGROUND: Aspiration pneumonia is a major complication that occurs in patients with severe cerebral palsy and is associated with their survival prognosis, necessitating appropriate assessment and response. We focused on swallowing frequency as an index of daily swallowing function due to the difficulty in evaluating the risk of pneumonia. The swallowing motion protects the airway by safely directing the food, saliva, and secretions accumulated in the pharynx into the esophagus to prevent aspiration and entry into the trachea. Thus, swallowing frequency may be correlated with the incidence of pneumonia. In this study, we aimed to investigate the relationship between swallowing frequency and history of pneumonia in patients with severe cerebral palsy. METHODS: Fifty-seven patients with cerebral palsy were included in this study. Swallowing frequency was measured three times for each patient on separate days, and the reproducibility was examined by calculating the intraclass correlation coefficient. Further, the relationship between swallowing frequency and history of pneumonia was investigated using multivariate logistic regression analysis. RESULTS: While swallowing frequency differed between participants, it was constant within individuals (intraclass correlation coefficient: 0.941). Furthermore, the swallowing frequencies per hour were 12.2 ± 12.2 and 27.0 ± 20.4 in the patient groups with and without a history of pneumonia, respectively (P < 0.001). Swallowing frequency (odds ratio: 10.489, 95% confidence interval: 2.706–40.663, P = 0.001) was significantly associated with the incidence of pneumonia in the previous year. CONCLUSIONS: Swallowing frequency could be used as an index for assessing the risk of dysphagia and pneumonia in patients with severe cerebral palsy.