Pneumonia risk and its associated factors in Parkinson's disease: A National Database Study

Despite pneumonia being an emerging burden on Parkinson's disease patients, there is essentially nothing known on whether they are at an increased risk of pneumonia occurrence and their associated factors.

To determine whether Parkinson's disease is associated with the risk of pneumonia and its associated factors.

Using nationwide database that covers the whole population in South Korea from 2002 to 2017, we identified newly diagnosed Parkinson's disease patients in 2004-2006, and selected four age- and sex-matched controls for each patient from the general population. From these patients and controls, we identified pneumonia occurrence until the end of the study period, and plotted Kaplan-Meier curves and Cox proportional hazards model to determine its risk.

We identified 10,159 Parkinson's disease patients and matched 39,574 controls. These patients showed a higher incidence rate than controls (11.21 vs. 3.61 events/1000 person-years) throughout the study period, and were at an increased risk of pneumonia (hazard ratio = 2.26; 95% CI, 2.17-2.36) even after adjusting for confounders. Old age, male sex, region of residence, diabetes mellitus, congestive heart failure, tuberculosis, atrial fibrillation, chronic kidney disease, cerebrovascular disease, dementia, chronic obstructive pulmonary disease, seizure disorder and antidiabetic drug usage were all associated with a higher risk of pneumonia, while dyslipidemia and antihypertensive medication usage lowered the risk.

Parkinson's disease patients may be more likely to experience pneumonia compared to the general population throughout the disease course from diagnosis. Therefore, physicians should focus on the modifiable risk factors of pneumonia in such patients.