New study shows communication errors are frequently the root cause of medical errors

July 30, 2004

Contact: Maureen Maxwell
(202) 232-9033 or (800) 274-2237, Ext. 2560

WASHINGTON -- A new study suggests that most medical errors in family medicine are set in motion by errors in communication. The authors assert that by examining the chain of events preceding medical errors, researchers can more accurately identify the underlying causes of medical errors and, in turn, more effectively direct efforts to prevent them.

"A String of Mistakes: The Importance of Cascade Analysis in Describing, Counting, and Preventing Medical Errors" was published in the July/August 2004 issue of Annals of Family Medicine.

"Cascade analysis reveals the story line of errors," explained Steven H. Woolf, M.D., M.P.H., lead author and a professor with the Department of Family Practice at Virginia Commonwealth University. "Errors are difficult to measure, not only because of inadequate reporting and varied definitions, but also because most error incidents are not single acts but chains of events. Researchers and administrators who ignore this complexity may produce skewed statistics about the consequences of errors and recommend misdirected solutions."

From June to December 2001, primary care physicians used a secure Internet connection to file anonymous reports of practice errors. Only the harms and costs affecting patients were counted and classified. Three categories of harm were used: physical injuries (physical health complications from errors during the reporting period), errors that had no reported immediate effect but that heightened the patient's risk for complications after the reporting period (such as poor control of hypertension), and psychological or emotional injuries (such as frustration or anger).

Findings include:

The 75 narratives described 184 errors, 83 proximal - first or underlying - errors, and 84 distal - final or ultimate - errors.

A chain of errors was documented in 58 of the 75 reports. Of these, 33 incidents included at least two errors, 17 had three, and eight had four errors.

The most conspicuous finding was the frequency with which the final errors in the reported incidents were precipitated by errors in communication. Errors in communication set off 47 of the 75 incidents reported by the physicians. Of the 64 errors in communication reported by the physicians (some incidents involved more than one error in communication), 57 were informational miscommunication that might have been prevented through the use of computers or other information systems.

For the 45 incidents in which physicians reported errors involving treatment, 10 were preceded by other errors in treatment, i.e. one mistake in treatment giving rise to another. In 12 cases, treatment errors were preceded by diagnostic errors, and in five cases, two or more diagnostic errors precipitated the treatment error.

Physicians appeared reluctant to acknowledge that patients were harmed, even when harm was mentioned in their narratives. Psychological and emotional effects accounted for only 17 percent of the health consequences reported by physicians but 69 percent of the health consequences inferred by investigators.


"In this and other studies, we have found that physicians and other staff rarely report on the emotional, financial, and psychological harms that patients experience as a result of errors," explained Robert L. Phillips Jr., M.D., co-author of the study and assistant director of the Robert Graham Center: Policy Studies in Family Practice and Primary Care in Washington, D.C. "It isn't clear why they don't consider these other real harms that patients experience, but it does suggest that error-reporting systems need to develop ways of assessing harm in addition to the primary reporters."

The authors pointed out several research and policy implications of their findings:

Claims about which errors are most common in medicine should be made and interpreted with caution.

Epidemiological studies and policy programs should move away from treating error incidents as single events and should instead use analytic methods, such as cascade analysis, to expose causal relationships and solutions.

Diagnostic and treatment errors often begin with errors in communication, and safety initiatives should focus more on management systems than is done currently in order to enhance the quality of information transfer.

Amid doubts that an ideal error-reporting system can be developed, it might be more important to focus on whether the system is designed to relate enough of the story line to facilitate cascade and root cause analysis. Amid doubts that an ideal error-reporting system can be developed, it might be more important to focus on whether the system is designed to relate enough of the story line to facilitate cascade and root cause analysis.

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Note to journalists: To interview the authors of the study or to obtain a copy of the article, please contact Maureen Maxwell at (202) 232-9033, (800) 274-2237, Ext. 2560, or

The Annals of Family Medicine is a peer-reviewed research journal dedicated to advancing knowledge essential to understanding and improving health and primary care. It is sponsored by the American Academy of Family Physicians, American Board of Family Practice, Society of Teachers of Family Medicine, Association of Departments of Family Medicine, Association of Family Practice Residency Directors, and the North American Primary Care Research Group.

The Robert Graham Center conducts research and analysis that brings a family practice perspective to health policy deliberations in Washington. Founded in 1999, the Center is an independent research unit working under the personnel and financial policies of the American Academy of Family Physicians. For more information, please visit

The information and opinions contained in research from the Robert Graham Center do not necessarily reflect the views or policy of the AAFP.

July 01, 2004