Effectiveness of the Osaka Metropolitan University Hospital Eating and Swallowing Manual for Dysphagia Triage in Patients at Admission: A Retrospective, Comparative Cross-Sectional Study

Background Aspiration pneumonia is a potentially fatal condition that is more commonly seen in older people and has a high mortality rate. As the world population is aging, aspiration pneumonia may likely become more common worldwide, including Japan and the United States. Although aspiration pneumonia is regarded as a preventable condition, its prevention is attracting a great deal of attention, with many published studies reporting screening tests. We developed the Osaka Metropolitan University Hospital Eating and Swallowing (OMUES) manual for dysphagia triage in all hospitalized patients to prevent aspiration pneumonia. In this study, we investigated the effectiveness of the OMUES manual for dysphagia triage in hospitalized patients by assessing changes in the incidence of aspiration pneumonia after introducing the OMUES manual. Materials and method The OMUES manual is designed for use by nurses without didactic training. Inpatients who meet the criteria for using the OMUES manual undergo a swallowing function assessment in three stages: the Eating Assessment Tool-10 (EAT-10) (stage 1), the Repetitive Saliva Swallowing Test (RSST) (stage 2), and the eating scene observation (stage 3). The study participants included 12,395 patients (6,000 males and 6,395 females) who were admitted between September 1, 2021, and August 31, 2022, excluding minors, patients with aspiration pneumonia on admission, and patients on emergency hospitalization, whose data were retrospectively extracted from the electronic medical records. These patients were examined in two groups: before and after introducing the OMUES manual. We closely examined patients with aspiration pneumonia to identify the cause and compared these between the two groups. Furthermore, as a secondary analysis, we also evaluated the implementation status of the OMUES manual. Results Before introducing the OMUES manual, there were 6,546 patients (3,164 males/3,382 females) and 52 patients with aspiration pneumonia (0.8%). After introducing the OMUES manual, the number of patients was 5,849 (2,836 males/3,013 females) and 42 cases (0.7%) with aspiration pneumonia. No statistically significant difference was observed between the two groups. As for the causes of aspiration pneumonia, factors associated with poor arousal were significantly reduced after introducing the OMUES manual, but the number of iatrogenic cases remained unchanged (21/52 cases [40.4%] and 19/42 cases [45.2%] before and after introducing the OMUES manual, respectively). The majority were associated with upper gastrointestinal endoscopy. The utilization rate was 92.5% in stage 1 of the OMUES manual, 50.9% in stage 2, and 60.0% in stage 3. The OMUES manual utilization rate, calculated by multiplying the utilization rates at each of stages 1, 2, and 3, was 28.3%. Conclusions We investigated the effectiveness of using the OMUES manual for dysphagia triage on all hospitalized patients. Although there was no statistically significant difference in the incidence of aspiration pneumonia before and after introducing the OMUES manual, our results suggest that it is contributing to its prevention. In addition, endoscopic examination revealed cases of aspiration pneumonia even in patients with normal swallowing function, and further investigation is required.