The impact of oral hygiene and oral function on the development and recurrence of aspiration pneumonia in elderly inpatients: a retrospective cohort study

Abstract

Abstract Background We examined the impact of oral hygiene and oral function on the development and recurrence of aspiration pneumonia (AP) in elderly inpatients. Methods The study enrolled 991 individuals who were eligible for swallowing function assessments at the Department of Oral and Maxillofacial Surgery at Noto General Hospital from March 2009 to March 2015. Participants were divided into a group diagnosed with AP (AP group) and non-AP (NP) group, and a comparative analysis of oral hygiene factors and oral functional factors was conducted between the two groups. The AP group was then further snbdivided into a recurrent AP (rAP) group, consisting of those who had experienced repeated pneumonia episodes, and a non-recurrent AP (nrAP) group, consisting of those who had not experienced recurrent pneumonia episodes, and the above factors were compared between them. Results In the comparative analysis between the AP group and NP group using simple regression, significant differences in oral hygiene factors s—namely, membranous substances, xerostomia, tongue fur, mucositis, and food residue—were observed. With respect to oral functional factors, only occlusion was significantly different between the groups (p < 0.0001). The results of a multivariate logistic regression analysis revealed that membranous substances (p < 0.001), fur (p = 0.0351), food residue (p < 0.001), and occlusion (p < 0.001) were factors that influenced the development of AP. In comparative analysis between the rAP group and nrAP group using simple regression, the significantly different oral hygiene factors were xerostomia (p = 0.03), mucositis (p = 0.019), and food residue (p = 0.02), and the significantly different oral functional factors were food bolus forming grade (FBFG) (p < 0.0001) and food intake level scale (FILS) (p < 0.0001). The results of the multivariate logistic regression analysis extracted mucositis (p = 0.0244), FBFG (p = 0.0213), and FILS (p = 0.011) as factors influencing the recurrence of AP. Conclusion These results suggested that, in elderly inpatients, oral hygiene plays a role in the development of AP and oral function may have an influence on its recurrence.