Decrease in food intake and mortality risks of elderly individuals indicated by the reason for decreased food intake : A retrospective cohort study

Background：Elderly individuals who gradually reach their deaths due to dementia or senility pass away from decreased food intake. The objective of the present study was to analyze frequency of specific reasons for decreased food intake and the amount of decrease noted in electronic patient records in order to elucidate mortality risks. Methods：This retrospective cohort study targeted 131 elderly people who were admitted to a nursing home for at least 6 months between 2011 and 2016 and passed away at the nursing home. We identified reasons for the decrease in food intake from their electronic patient records and statistically analyzed the correlation between the frequency of specific words and decrease in mean food intake （kcal） and the correlation between decreased food intake and mortality risk. Results：Words related to the reasons for inability to eat were identified. Words such as “difficulty opening the mouth”, “oversleeping”, “phlegm”, and “refusal” were used often and showed strong negative correlation with food intake （r>-0.930, p<.0001）. Food intake significantly continued to decrease from nine months prior to death to the time of death. An ROC analysis detected significant difference in the amount of change between nine months prior to death and the nine months before that point （<0.001）, where AUC was 0.929 and the odds ratio was 26.93.Conclusions：It was verified that an increase in mortality risk of elderly individuals, who receive long-term care and pass away from dementia or senility, was certain, when food intake continues to decrease significantly due to reasons such as individuals not being fully awake during meals, inadequate swallowing and airway clearance, and refusal of meals.