title: Risk factors for pneumonia among patients with Parkinson's disease: a Taiwan nationwide population-based study.
abstract: OBJECTIVE
  Pneumonia is the leading cause of death in patients with Parkinson's disease (PD). However, few studies have been performed to explore the risk factors for pneumonia development in patients with PD.
  
  
  METHODS
  We conducted a nationwide population-based cohort study of patients with PD to identify the risk factors for these patients developing pneumonia. Participants with newly diagnosed PD between 2000 and 2009 were enrolled from the 2000-2010 National Health Insurance Research Database in Taiwan. We compared patients with PD with an incidence of hospitalization with pneumonia vs those without, and Cox proportional hazard models were used to estimate the risk of pneumonia.
  
  
  RESULTS
  Of the 2,001 enrolled patients (mean follow-up duration 5.8 years, range: 2.7-14.7 years), 381 (19.0%) had an incidence of hospitalization with pneumonia during the study period. Multivariate Cox proportional hazards analysis identified older age group (≥80 years of age, hazard ratio [HR] =3.15 [95% confidence interval 2.32-4.28]), male sex (HR =1.59 [1.29-1.96]), certain geographic regions (northern, HR =1.36 [1.04-1.78], southern and eastern, HR =1.40 [1.05-1.88]), rural areas (HR =1.34 [1.05-1.72]), chronic heart failure (HR =1.53 [1.02-2.29]), and chronic kidney disease (HR =1.39 [1.03-1.90]) as risk factors for hospitalization with pneumonia in patients with PD. However, treatment for dental caries was a protective factor (HR =0.80 [0.64-0.99]).
  
  
  CONCLUSIONS
  The results of this study highlight risk factors that are associated with hospitalization with pneumonia, and, for the first time, suggest a link between treated dental caries and a diminished risk of hospitalization with pneumonia in patients with PD.
authors.affiliation: Department of Neurology, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.
authors.forename: Yang-Pei
authors.initials: YP
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.
authors.forename: Chih-Jen
authors.initials: CJ
authors.lastname: Yang
authors.affiliation: Department of Dentistry, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.
authors.forename: Kai-Fang
authors.initials: KF
authors.lastname: Hu
authors.affiliation: Department of Neurology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.
authors.forename: A-Ching
authors.initials: AC
authors.lastname: Chao
authors.affiliation: Department of Management, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.
authors.forename: Yu-Han
authors.initials: YH
authors.lastname: Chang
authors.affiliation: School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.
authors.forename: Kun-Pin
authors.initials: KP
authors.lastname: Hsieh
authors.affiliation: Department of Psychiatry, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.
authors.forename: Jui-Hsiu
authors.initials: JH
authors.lastname: Tsai
authors.affiliation: Faculty of Dental Hygiene, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China; Cancer Center, Kaohsiung Medical University Chung-Ho Memorial Hospital, Kaohsiung, Taiwan, Republic of China.
authors.forename: Pei-Shan
authors.initials: PS
authors.lastname: Ho
authors.affiliation: Faculty of Medicine, University of Malaya, Kuala lumpur, Malaysia.
authors.forename: Shen-Yang
authors.initials: SY
authors.lastname: Lim
keywords: Parkinson’s disease; chronic heart failure; chronic kidney disease; dental caries; pneumonia