You are here:
Application of a large electronic health record database to study effects of air quality on mortality in a heart failure population
Citation:
Weaver, A., E. Pfaff, J. Champion, W. Cascio, R. Devlin, L. Neas, D. Diaz-Sanchez, AND C. Ward-Caviness. Application of a large electronic health record database to study effects of air quality on mortality in a heart failure population. NC Breathe Conference, Winston-Salem, North Carolina, March 08, 2018.
Impact/Purpose:
In recent years, medical records have become digital, and almost all healthcare facilities in the US now use electronic health records (EHRs). EHRs provide detailed information on all patients. For that reason, there are many potential research uses for EHRs, including environmental health. However, EHRs have not been widely used for environmental health studies. We linked heart failure patients at University of North Carolina Hospitals to air pollution data by geocoding their billing addresses. We obtained records from 41,913 heart failure patients; we were able to geocode addresses at the zip code or street level for all but 66. Preliminary results show strong associations between fine particulate matter air pollution (PM2.5) and mortality among heart failure patients in North Carolina. We plan on using procedures developed here for future studies using data from EHRs. This project expands the scope of environmental health research to use data from EHRs, with tens of thousands or potentially millions of participants.
Description:
Background: Electronic health records (EHRs) are now a ubiquitous component of the US healthcare system and are attractive for secondary data analysis as they contain detailed and longitudinal clinical records on potentially millions of individuals. However, due to their relative novelty, the strengths and limitations of such databases for environmental research have not been well explored. Here we use EHRs to study environmental risks in heart failure (HF) patients, an understudied group of individuals. Method: The Carolina Data Warehouse (CDW) is a large database of EHRs from individuals who visited a UNC-affiliated hospital from July 1st, 2004 onward. Since inception, the number of hospitals and patients submitting data to the CDW has steadily increased. Though detailed, these clinical records are not optimized for environmental health studies. We obtained longitudinal records from 41,913 HF patients who presented to a UNC hospital between 07/01/2004 and 12/31/2016. Using address data provided in hospital billing records, we obtained 48,287 addresses; 40,874 were geocoded to street level, 7,347 to the zip code, 49 to the city, and 17 patients did not have a valid address at any visit. Using data from the EPA’s network of monitors, as well as estimated air pollution based on satellite imaging, we are able to show strong associations between exposure to particulate matter < 2.5µm in diameter and natural cause, cardiovascular, and cardiopulmonary mortality. Though preliminary, these results suggest that the association between air quality and mortality in this population may be substantially higher than that observed in the general population. Conclusion: As EHRs become more prevalent, and as standardized access for research purposes increases, it will be important for researchers to utilize these novel resources in a carefully considered manner to understand relationships between air pollution exposure and health outcomes. This abstract does not necessarily reflect EPA policy.