Risk factors for mortality in aspiration pneumonia: a single-center retrospective observational study

Submitted: May 6, 2022
Accepted: October 3, 2022
Published: October 13, 2022
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Aspiration pneumonia (AP) is the leading cause of death among the elderly in Japan. The factors associated with the survival of elderly patients with AP are investigated in this retrospective observational study. Patients with AP over the age of 60 who were assessed for swallowing function in our hospital between April 2015 and March 2016 were eligible. Data on patients' body mass index (BMI), food consistency, and Karnofsky performance status were collected from medical records in hospital and again after recovery. Following hospital discharge, eligible patients were sent questionnaires containing information about their physical conditions, such as body weight and the Japanese version of the functional independence measure. Respondents were divided into two groups: those who died and those who survived, and the factors associated with patient mortality were investigated. There were 19 responses from 50 eligible patients, and seven patients died. The participants' average age was 81 years (SD 9.32). There were ten male participants (52.6%, p=1.00), and there were no significant differences in the mortality and survival groups. The most significant finding was that BMI was significantly lower in the patients who died (p=0.037, Cohen’s d=1.10). Fisher's exact tests clearly demonstrated that patients with a BMI <19.9 had a higher mortality rate (p=0.017). Lower BMI may be associated with increased mortality in elderly patients with a history of AP. In general practice, BMI is simple to measure and may allow for an easy assessment of the risk of AP-related mortality.



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Statistics Bureau of the Ministry of Internal Affairs and Communications. [National census results].[In Japanese]. Tokyo: Ministry of Internal Affairs and Communications; 2018. Available from: https://www.mhlw.go.jp/toukei/saikin/hw/jinkou/kakutei18/index.html
Teramoto S, Fukuchi Y, Sasaki H, et al. High incidence of aspiration pneumonia in community- and hospital-acquired pneumonia in hospitalized patients: a multicenter, prospective study in Japan. J Am Geriatr Soc 2008;56:577-9. DOI: https://doi.org/10.1111/j.1532-5415.2008.01597.x
Suzuki J, Ikeda R, Kato K, et al. Characteristics of aspiration pneumonia patients in acute care hospitals: A multicenter, retrospective survey in Northern Japan. PLoS One 2021;30;16:e0254261. DOI: https://doi.org/10.1371/journal.pone.0254261
Mandell LA, and Niederman MS. Aspiration pneumonia. N Engl J Med 2019;380:651-63. DOI: https://doi.org/10.1056/NEJMra1714562
Manabe T, Teramoto S, Tamiya N, et al. Risk factors for aspiration pneumonia in older adults. PLoS One 2015;10:e0140060. DOI: https://doi.org/10.1371/journal.pone.0140060
Feng M-C, Lin Y-C, Chang Y-H, et al. The mortality and the risk of aspiration pneumonia related with dysphagia in stroke patients. J Stroke Cerebrovasc Dis 2019;28:1381-7. DOI: https://doi.org/10.1016/j.jstrokecerebrovasdis.2019.02.011
Asgedom SW, Gidey Kiday, Gidey Kidu, et al. Medical complications and mortality of hospitalized stroke patients. J Stroke Cerebrovasc Dis 2020;29:104990. DOI: https://doi.org/10.1016/j.jstrokecerebrovasdis.2020.104990
Bosch X, Formiga F, Cuerpo S, et al. Aspiration pneumonia in old patients with dementia. Prognostic factors of mortality. Eur J Intern Med 2012;23:720-6. DOI: https://doi.org/10.1016/j.ejim.2012.08.006
Takizawa C, Gemmell E, Kenworthy J, et al. A systematic review of the prevalence of oropharyngeal dysphagia in stroke, Parkinson's disease, Alzheimer's disease, head injury, and pneumonia. Dysphasia 2016;31:434-41. DOI: https://doi.org/10.1007/s00455-016-9695-9
Yoon H-Y, Shim SS, Kim SJ, et al. Long-term mortality and prognostic factors in aspiration pneumonia. J Am Med Dir Assoc 2019;20:1098-104.e4. DOI: https://doi.org/10.1016/j.jamda.2019.03.029
Wei C, Cheng Z, Zhang L, et al. Microbiology and prognostic factors of hospital- and community-acquired aspiration pneumonia in respiratory intensive care unit. Am J Infect Control 2013;41:880-4. DOI: https://doi.org/10.1016/j.ajic.2013.01.007
Hirakawa Y, Masuda Y, Kuzuya M, et al. [Decision-making factors regarding resuscitate and hospitalize orders by families of elderly persons on admission to a Japanese long-term care hospital].[Article in Japanese]. Nihon Ronen Igakkai Zasshi. 2007;44:497-502. DOI: https://doi.org/10.3143/geriatrics.44.497
Ashley C Rider, Bradly W Frazee. Community-acquired pneumonia. Emerg Med Clin North Am 2018;36:665-83. DOI: https://doi.org/10.1016/j.emc.2018.07.001
Komiya K, Ishii H, Umeki K, et al. Impact of aspiration pneumonia in patients with community-acquired pneumonia and healthcare-associated pneumonia: a multicenter retrospective cohort study. Respirology 2013;18:514-21. DOI: https://doi.org/10.1111/resp.12029
Robbins J, Gensler G, Hind J, et al. Comparison of 2 interventions for liquid aspiration on pneumonia incidence: a randomized trial. Ann Intern Med 2008;148:509-18. DOI: https://doi.org/10.7326/0003-4819-148-7-200804010-00007
Ohta T, Waga S, Handa W, et al. [New grading of level of disordered consciousness].[Article in Japanese]. No Shinkei Geka 1974;2:623-7.
Japanese Society of Dysphasia Rehabilitation dysphagia diet committee. [Japanese Dysphagia Diet 2013].[Article in Japanese]. Jap J Dysph Rehabil 2013;18:255-67.
Keith RA, Granger CV, Hamilton BB, et al. The functional independence measure: a new tool for rehabilitation. Adv Clin Rehabil1987;1:6-18.
Maeda K, Akagi J. Muscle mass loss is a potential predictor of 90 day mortality in older adults with aspiration pneumonia. J Am Geriatr Soc 2017;65:e18-e22. DOI: https://doi.org/10.1111/jgs.14543
Maeda K, Mori N. Poor oral health and mortality in geriatric patients admitted to an acute hospital: an observational study. BMC Geriatr 2020 28;20:26. DOI: https://doi.org/10.1186/s12877-020-1429-z
Akuzawa N, Yoshii A, Ono A, et al. Predictors of discontinuance of oral feeding in patients with advanced Alzheimer dementia and aspiration pneumonia in Japan: A single-center, retrospective observational study. Alzheimer Dis Assoc Disord 2019;33:339-45. DOI: https://doi.org/10.1097/WAD.0000000000000316
Maeda K, Takaki M, and Akagi J. Decreased skeletal muscle mass and risk factors of sarcopenic dysphagia: A prospective observational cohort study. J Gerontol Biol Sci Med Sci 2017;72:1290-4. DOI: https://doi.org/10.1093/gerona/glw190
Okazaki T, Ebihara S, Mori T, Izumi S, Ebihara T. Association between sarcopenia and pneumonia in older people. Geriatr Gerontol Int 2020;20:7-13. DOI: https://doi.org/10.1111/ggi.13839
Cruz-Jentoft AJ, Sayer AA. Sarcopenia. Lancet 2019;393:2636-46. DOI: https://doi.org/10.1016/S0140-6736(19)31138-9

Ethics Approval

The authors have no potential conflicts of interest to declare. Naoto Ishimaru is employed by the Aijinkai Healthcare Corporation. Madoka Ito has received grants from the Aijinkai Healthcare Corporation

How to Cite

Ito, Madoka, Naoto Ishimaru, Toshio Shimokawa, and Yoshiyuki Kizawa. 2022. “Risk Factors for Mortality in Aspiration Pneumonia: A Single-Center Retrospective Observational Study”. Monaldi Archives for Chest Disease 93 (3). https://doi.org/10.4081/monaldi.2022.2305.