Background: Increasing numbers of patients require medical interpretation, yet few studies have examined its accuracy or effect on health outcomes.
Objective: To understand how alterations in medical interpretation affect health care delivery to patients with limited English proficiency (LEP), we aimed to determine the frequency, type, and clinical significance of alterations. We focused on best-case encounters that involved trained, experienced interpreters interacting with established patients.
Design: We audio-recorded routine outpatient clinic visits in which a medical interpreter participated. Audiotapes were transcribed and translated into English. We identified and characterized alterations in interpretation and calculated their prevalence.
Participants: In total, 38 patients, 16 interpreters, and 5 providers took part. Patients spoke Cantonese, Mandarin, Somali, Spanish, and Vietnamese, and received care for common chronic health conditions.
Measures: Unlike previous methods that report numbers of alterations per interpreted encounter, we focused on alterations per utterance, which we defined as the unit of spoken content given to the interpreter to interpret. All alteration rates were calculated by dividing the number of alterations made during the encounter by the number of utterances for that encounter. We defined clinically significant changes as those with potential consequences for evaluation and treatment.
Key results: We found that 31% of all utterances during a routine clinical encounter contained an alteration. Only 5% of alterations were clinically significant, with 1% having a positive effect and 4% having a negative effect on the clinical encounter.
Conclusion: Even in a best case scenario, the rate of alteration remains substantial. Training interpreters and clinicians to address common patterns of alteration will markedly improve the quality of communication between providers and LEP patients.