Trained medical interpreters can reduce errors in care for patients with limited English proficiency

For patients with limited English proficiency (LEP), errors in medical interpretation are common—especially when the interpreter is a family member or other untrained person, reports a study in the October issue of Medical Care.

The error rate is cut in half when trained medical interpreters are used, whether in person or by video conference, according to the research by Dr. Eliseo J. Pérez-Stable and colleagues of University of California, San Francisco. They conclude, "Full deployment of professional interpretation capacity for LEP patients is a quality of care issue whose time has come." (Dr. Pérez-Stable is now Director of the National Institute of Minority Health and Health Disparities, Bethesda, Md.)

Higher Accuracy in Visits with Professional Medical Interpreters

The study assessed the accuracy of medical interpretation during 32 primary care visits with Spanish-speaking Latino patients at a public hospital clinic. Visits were audiotaped and transcribed, and analyzed to determine the rate of errors in medical interpretation—including errors likely to have a "clinically significant" impact on patient care.

The analysis focused on differences in error rates for visits with professional interpreters, either in-person or via video conference; or with untrained "ad hoc" interpreters, usually a member of the patient's family. Rates of clinically significant errors were also compared between groups.

The overall error rate was about 30 percent, based on the number of "text units" analyzed. Errors of omission and answering for the patient or health care professional were the most common types of interpreter errors.

Trained interpreters were more accurate whether they provided services in person or by video conference. Errors were about twice as common in visits with ad hoc interpreters: 54 percent, compared to 25 percent with trained interpreters. These differences remained statistically significant after adjustment for other patient- and visit-related factors.

About seven percent of errors were rated clinically significant: for example, an incorrect drug dosage or inaccurately describing the patient's symptoms. On average, there were one or two "moderately or highly clinically significant errors" during visits with ad hoc interpreters.

The odds of a clinically significant error were about 75 percent lower in visits with trained in-person interpreters compared to ad hoc interpreters. These effects remained statistically significant after adjustment for patient- and visit-related factors.

Clinics and hospitals receiving federal funds are required to provide interpretation services, either by bilingual staff or professional interpreters, for patients with LEP. "Compared to English-speaking patients, LEP patients suffer poorer quality of care," Dr. Pérez-Stable and coauthors write.

Interpreter services can lessen the impact of these disparities for LEP patients. However, the demand for professional interpretation services exceeds the availability, and this gap is likely to grow wider in the future.

The results add to previous evidence showing that medical interpretation errors are common in visits with LEP patients—and may be more than twice as frequent when untrained interpreters are used. The risk of errors, including clinically significant errors, is significantly lower in visits with professional interpreters, whether in person or by video conference. Dr. Pérez-Stable and colleagues conclude, "Professional video conferencing interpretation in particular, appears to be well accepted by patients and may be a cost-effective method for expanding access to professional interpretation services to meet quality standards."