Mortality From Parkinson's Disease With Influenza and Pneumonia as Contributing Causes in the United States, 1999-2020.

BACKGROUND

Parkinson's disease (PD) is a progressive neurodegenerative disorder and a leading cause of morbidity and mortality among older adults. Respiratory infections such as influenza and pneumonia further increase mortality due to impaired cough reflex, dysphagia, and reduced immunity. Limited research has examined long-term mortality trends where these infections contribute to PD-related deaths.

AIMS AND OBJECTIVES

This study aimed to evaluate the crude and age-adjusted mortality rates (AAMRs) of individuals with PD where influenza or pneumonia were contributing factors.

METHODS

We conducted a retrospective study using the CDC Wide-Ranging Online Data for Epidemiologic Research (WONDER) Multiple Cause of Death (MCD) database (1999-2020). Individuals aged ≥45 years with PD (ICD-10: G20) as the underlying cause of death and influenza or pneumonia (ICD-10: J09-J18) as contributing causes were included. Mortality rates were calculated per 1,000,000 population and age-adjusted to the 2000 US Standard Population. Demographic, geographic, and temporal patterns were analyzed using JoinPoint regression.

RESULTS

From 1999 to 2020, 43,644 deaths were identified. Males accounted for 28,831 deaths (66.1%), and White individuals accounted for 40,716 deaths (93.3%). Most deaths occurred in metropolitan areas (35,261 deaths, 80.8%) and nursing homes/long-term care facilities (19,223 deaths, 44%). The crude mortality rate was 16.6 per 1,000,000 population. AAMRs showed a significant overall decline (annual percentage change (APC), -4.41%; p < 0.05). Male mortality remained consistently higher than female mortality (14,813 deaths, 33.9%). Racial disparities were observed, with White individuals showing the greatest burden (40,716 deaths, 93.3%), while Black (1,581 deaths, 3.6%) and Asian or Pacific Islander groups (1,205 deaths, 2.8%) demonstrated fluctuating but declining trends.

CONCLUSION

Mortality from PD with influenza or pneumonia declined significantly between 1999 and 2020, reflecting improvements in infection control and elderly care. However, disparities by sex, race, and geography persist, underscoring the need for targeted interventions, particularly in long-term care settings.