Pneumonia Risk Increased by Dementia-Related Daily Living Difficulties: Poor Oral Hygiene and Dysphagia as Contributing Factors

Abstract

Although pneumonia is the leading cause of death among patients with dementia, the specific underlying causes remain unclear. In particular, the potential connection between pneumonia risk and dementia-related daily living difficulties, such as oral hygiene practice and mobility impairment, and the use of physical restraint as a management practice, has not been extensively studied. In our retrospective study, we included 454 admissions corresponding to 336 individual patients with dementia who were admitted to a neuropsychiatric unit due to behavioral and psychological symptoms. The admissions were divided into two groups: those who developed pneumonia while hospitalized (n=62) and those who did not (n=392). We investigated differences between the two groups in terms of dementia etiology, dementia severity, physical conditions, medical complications, medication, dementia-related difficulties in daily living, and physical restraint. To control potential confounding variables, we used mixed effects logistic regression analysis to identify risk factors for pneumonia in this cohort. Our study found that the development of pneumonia in patients with dementia was associated with poor oral hygiene, dysphagia, and loss of consciousness. Physical restraint and mobility impairment showed a weaker, nonsignificant association with the development of pneumonia. Our findings suggest that pneumonia in this population may be caused by two primary factors: increased pathogenic microorganisms in the oral cavity due to poor hygiene, and an inability to clear aspirated contents due to dysphagia and loss of consciousness. Further investigation is needed to clarify the relationship between physical restraint, mobility impairment, and pneumonia in this population.