Electronic Health Records a Promising Public Health Tool

Using electronic medical histories for public health surveillance could save money, complement existing urban health data sources

Thursday, April 20 2017

Electronic versions of patients’ medical history, known as electronic health records (EHR), were originally designed to better track an individual’s health, but new research by colleagues from the New York City Department of Health and Mental Hygiene and Lorna Thorpe, PhD, professor and director of the Division of Epidemiology at NYU School of Medicine’s Department of Population Health, finds EHRs can serve an important public health service: aiding cities in better understanding the health of their communities. EHRs are becoming the standard of care in doctor’s offices, with 87 percent of medical practices nationwide using some kind of EHR system in 2015. 

A cross-disciplinary team of epidemiologists, health information technology experts, and clinicians developed the NYC Macroscope, which aggregates data from the electronic health records of primary care practices across New York City serving more than 700,000 patients, looking at key health indicators including prevalence of diabetes, hypertension, smoking, depression, and obesity.

The team found that EHRs were equally accurate for measuring the burden of some common chronic diseases as statistically-representative in-person examination surveys and telephone surveys that city health departments have traditionally used to gather data about their citizens’ health, which they reported in a perspective piece for the American Journal of Public Health, published April 20, and a series of articles published in AcademyHealth’s eGEMs journal last December.

“Our use of the NYC Macroscope suggests that electronic health records can complement existing public health surveillance tools and help in setting priorities,” said Dr. Thorpe, a lead and senior author on two of the eGEMs papers, and co-author on the other eGEMs paper and the AJPH piece. “This is exciting news because surveys can be costly and time consuming for health departments and, in recent decades, response rates to surveys have been declining.”

To measure accuracy, the investigators compared the EHR data from the NYC Macroscope in 2013 to estimates from two surveys the city uses to collect health data on New Yorkers: the NYC Health and Nutrition Examination Survey, known as NYC HANES, and the NYC Community Health Survey.

The NYC Macroscope and the two surveys had similar results for measuring diabetes, hypertension, smoking and obesity prevalence, but NYC Macroscope proved less accurate for high cholesterol, depression, and influenza vaccination.

“While indicator performance was variable, findings here confirm that a carefully constructed EHR-based surveillance system can generate prevalence estimates comparable to those from gold-standard examination surveys for certain conditions and risk factors,” the authors write.

“The NYC Health Department sees the NYC Macroscope as an important tool for population health surveillance in addition to our existing surveys, birth and death records and other sources of health information,” said Sharon E. Perlman, MPH, Director of Special Projects at the Division of Epidemiology in the NYC Department of Health and Mental Hygiene and lead author of the AJPH article.

This work was supported financially by the de Beaumont Foundation, the Robert Wood Johnson Foundation—including its National Coordinating Center for Public Health Services and Systems Research—the Robin Hood Foundation, the New York State Health Foundation, the Doris Duke Charitable Foundation, and the U.S. Centers for Disease Control and Prevention.

In the same issue of the American Journal of Public Health, Dr. Thorpe authors an editorial to inaugurate the journal’s new section on public health surveillance and survey methods. In it, she discusses two priorities in public health surveillance: making big data a reality in health care and improving measurement of the public’s health in small areas, such as urban neighborhoods—known as “small area estimation.” EHR-based surveillance can potentially advance both priorities, writes Dr. Thorpe.

In addition to Dr. Thorpe and Ms. Perlman, authors of the AJPH piece include Katharine McVeigh, PhD, Laura Jacobson, MSPH, Carolyn Greene, MD, and Deputy Commissioner of Epidemiology Charon Gwynn, PhD, of the NYC Health Department, and Dr. Thorpe. Dr. McVeigh, Remle Newton-Dame of NYC Health + Hospitals’ OneCity Health, and Dr. Thorpe were lead authors of the three eGEMS papers, with many co-authors from the NYC Macroscope team.

--Elaine Meyer