OHSU Studies Effectiveness of Computers in Identifying First Cases of Disease Outbreaks

10/02/03    Portland, Ore.

New surveillance process has already detected unusual number of viral meningitis cases.

A computerized patient information system in OHSU Hospital's emergency department (ED) may prove effective in helping detect unusual clusters of contagious disease cases like meningitis and West Nile virus. OHSU emergency medicine researchers are studying whether EMSTAT, a computer in the ED used to collect patient information for treatment purposes, can be used as an additional tool for public health agencies to detect disease outbreaks. The study is funded by the Centers for Disease Control and Prevention and the Oregon Department of Human Services.

The system showed promise when it detected 26 patients with symptoms of viral meningitis during the last three months. Usually these individual cases would've gone unreported. However, EMSTAT indicated this was an unusually high number of cases (i.e., a "cluster") considering the hospital usually treated just 13 cases during comparable time periods in the past. The computer was programmed to look for patients with viral meningitis symptoms because an unusual number of patients with these symptoms could indicate a public health concern. A public health investigation of OHSU's patients did not find any cases of encephalitis, West Nile virus or other serious health risks to the community.

Oregon public health agencies use a variety of surveillance systems to detect diseases of public health concern, but there is no "real-time" automated system to look for these infections in people. If OHSU's study proves that the patient information computer in the ED is an effective tool in early detection, it will help supplement the existing public health surveillance systems.

"If we can detect clusters of serious infectious early, we can notify public health officials and work with them to save lives," said Jonathan Jui, M.D., M.P.H., principal investigator for the study, emergency medicine physician and professor of emergency medicine in the OHSU School of Medicine.

Viral meningitis also is a good example of how this system can help detect diseases that do not warrant individual reporting to public health officials. ED health care providers on one shift who treat a viral meningitis case may not communicate that information with providers on other shifts because seeing a single case during a shift isn't unusual. However, the case seen during one shift is joined by others seen on later shifts, it may indicate a cluster of illness that should be investigated by public health officials to determine the cause and guide preventive action There are weaknesses in current systems that depend primarily on health care professionals identifying cases and then communicating with each other and with public health authorities.

Jui and his fellow researchers hope information systems like EMSTAT will bridge that communication gap and act as a watchdog for clusters of contagious disease cases. The computer logs symptoms, physical findings, county of residence and diagnoses, among other things.

Combining this information with a geographical mapping system in the ED, OHSU staff can track the types of diseases they are treating and where the patients are coming from on a daily basis, providing an early warning system for unusual trends.

OHSU has had EMSTAT for five years, accumulating data on more than 230,000 patients during that time. This historical data provides a baseline for comparison, allowing EMSTAT researchers to determine whether an observed pattern of information is truly unusual. For example, the database showed that the OHSU ED typically treats about five or six cases of viral meningitis each month. Seeing a cluster averaging more than eight cases per month stood out as an unusual event. This kind of cluster of cases warrants at least preliminary investigation by the local public health department. Results of the public health investigation are used to guide preventive action (e.g., providing information to the public, recommending vaccination, or taking environmental action if appropriate).

"The ability to track changes in the department patient data over time means we can see quickly when variations exceed normal levels," said Christopher Bangs, M.S., co-principal investigator and instructor in emergency medicine in the OHSU School of Medicine.

OHSU health care providers didn't report any of the suspected cases of viral meningitis to public health authorities because the individual cases weren't unusual for them. However, as EMSTAT tracked and collated the cases over time, it indicated the need to report them.

"This many cases is clearly something unusual for OHSU's ED. In the hospital's five years of data, we rarely have seen more than five or six cases in a month," said Jui.

Not all hospitals around the country have emergency department patient tracking systems that store as much information as OHSU's system. In addition, OHSU Hospital and Doernbecher Children's Hospital patients come not only from Portland, but from all areas of Oregon and the Northwest. This provides a unique window on the broad and diverse population seeking health care.

If the ED computer system proves to be an effective early detection method for meningitis and encephalitis, it could be programmed to detect other contagious diseases, such as pneumonia, influenza, SARS and diseases linked to bioterrorism (e.g., anthrax).

OHSU is collaborating on this project with the Multnomah County Health Department, Multnomah County Vector Control and the Oregon Department of Human Services.

EMSTAT is a product of A4 HEALTH SYSTEMS. A4 is dedicated to promoting community-based health care via HEALTHMATICS ELECTRONIC MEDICAL RECORD SOLUTIONS for consolidated clinical, financial and administrative patient information management. Founded in 1970, A4 has nationally implemented software and services in more than 1,100 health care organizations, including physician groups and practices, and emergency departments and hospitals.

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