Swallowing dysfunction and the onset of fever in older residents with special care needs: a thirteen-month longitudinal prospective study

A decline in swallowing function is frequently observed among older residents in nursing homes. We investigated whether swallowing dysfunction was related to the onset of fever in such individuals. Older residents aged ≥ 65 years from three nursing homes were included in this prospective study conducted from July 2017 to May 2019. The follow-up period was 13 months. The outcome was fever incidence in relation to the swallowing dysfunction. Baseline data on the activities of daily living, cognitive function, swallowing function, respiratory function, tongue pressure, and comorbidity conditions were collected. Dates on which the axillary temperature measured ay of participants was > 37.5 °C during the follow-up period were also recorded. For the statistical analyses, swallowing function assessed by the modified water swallow test (MWST) score was used to divide the participants into three groups: scores ≤ 3, 4, and 5. A total of 52 participants [median age, 89.5 years (67–104)] were enrolled. Kaplan–Meier analysis showed that the average periods until onset of fever in participants with MWST scores of ≤ 3, 4, and 5 were 8.0 (6.0–11.0), 10.0 (7.0–12.0), and 12.0 (10.0–13.0) months, respectively. Cox’s proportional hazards regression model revealed that participants with an MWST score ≤ 3 were at a higher risk of fever than those with an MWST score of 5 (hazard ratio 11.5, 95% confidence interval 1.5–63.4, adjusted for possible confounders. The swallowing dysfunction correlated with the risk of fever in older residents of nursing homes.