Establishing and Implementing Pneumonia Diagnosis in ED Older Adults: A Mixed Methods Approach

PROJECT SUMMARY/ABSTRACT
In the time it takes to read this application, 20 older adults (age≥65 years) will die of pneumonia in the
United States. Annually over 500,000 older adults received treatment in emergency departments (ED) for
pneumonia. Unfortunately, ED physicians cannot accurately diagnose pneumonia in older adults because of
atypical symptoms, chest x-ray inaccuracy, comorbidities, failure of pulmonary clinical prediction rules
established with younger adults, and poor accuracy of available biomarkers. Emergency physician’s inability to
diagnose pneumonia in older adults leads to delayed diagnosis, inadequate treatment, worsening infection,
longer lengths of stay (6.6 days vs. 5.4), and mortality.
Pneumonia can be caused by bacterial and viral pathogens alone or in combination. Bacterial
pneumonia alone causes the adverse outcomes and faces the diagnostic challenges just described. The
presence of viral pneumonia further complicates diagnosis. Bacterial and viral co-infection in all adults increase
odds of death by 2.1 with expected greater deleterious effects on older adults. Unfortunately, when viral
sources are detected our current diagnostic approach fails to reliably identify bacterial sources in the event of
co-infections. This can lead to inappropriate care and highlights the importance of ensuring fast, accurate
diagnosis of both bacterial and viral pneumonia.
Unfortunately, available tests (serum, imaging) and patient presentation (symptoms, exam, and history)
are unreliable for diagnosing pneumonia in older adult ED patients. Our previous results reveal that novel tests
may improve diagnostic accuracy of pneumonia (antimicrobial peptides [AMPs] and monocyte distribution
width [MDW]). AMPs are a part of the innate immune system and respond in minutes to bacteria and viruses.
Monocyte distribution width measures the distribution of size of leukocytes and increases in ED sepsis.
This project seeks to build on previous investigations to improve the diagnostic accuracy of pneumonia
in older adult ED patients with the long-term goal of improving clinical care and decreasing the morbidity and
mortality associated with pneumonia. Aim #1 examines the potential for novel tests (AMPs and MDW) to
diagnose pneumonia alone and in combination with patient presentation/symptoms and existing diagnostic
studies. This aim will consider pneumonia caused by bacterial pathogens, viral pathogens and the combination
separately to create and determine the accuracy of a diagnostic pathway. Aim #2 will employ group concept
mapping guided by the Theoretical Domains Framework to engage emergency physicians to identify facilitators
and barriers to implementation of a diagnostic pathway in emergency medicine to inform future studies. Aim #3
pilots the Aim #1 diagnostic pathway. If successful, this proposal will produce a diagnostic pathway for
pneumonia in older adult ED patients and provide the groundwork for a successful validation and
implementation study of this diagnostic pathway.

Grant Number: 3K76AG074941-04S1
NIH Institute/Center: NIH
Principal Investigator: Katherine Buck