Flores et al. found that interpreters made clinically significant alterations at alarmingly high rates2,13
. Although their study also concluded that trained medical interpreters were less prone to such alterations than were ad hoc
interpreters, their analyses nevertheless yielded rates of 53% and 77%, respectively, for trained vs. untrained interpreters. Flores et al. calculated alteration rates by summing the number of phrases interpreted over all encounters by a single interpreter (either professional or ad hoc
whereas we calculated alterations per utterance per encounter. Using this method, we found a rate of clinically significant alterations (5%) that was smaller by an order of magnitude than the rate found by Flores and colleagues, even for trained interpreters. The likely reasons behind these strikingly different findings are rooted in our intentional focus on a best case scenario with a professionally trained interpreter addressing a familiar topic with an established physician/patient dyad. Under these favorable circumstances, we established that about one-fifth of clinically significant changes actually enhanced rather than impeded communication between patient and physician.
Notably, an earlier study conducted at the same medical center reported that clinically significant changes comprised 78% of all interpreter alterations during family conferences in the intensive care unit29
. These encounters arguably represented a worst case scenario, as they involved complex medical cases, emotionally charged discussions, morbidly ill patients who were previously unknown to the provider, and interpreters provided by an agency rather than employed by the medical center.
Like Flores et al., we found that deletion was the most common alteration, even though the rates we observed (16%) were much lower than the ones they reported (51%)2
. Because we included five languages other than English, whereas their study addressed only Spanish, we were able to observe that overall rates of alteration varied by language, from 22% in Spanish-language encounters to 35% in Vietnamese-language encounters. Further study is required for an adequate understanding of this discrepancy.
While it is unlikely that the interaction among interpreter, provider, patient, and language can be completely teased apart, this complex relationship undoubtedly accounts for some of the significant differences between groups that we saw in pairwise comparisons. We conclude that professional training programs for interpreters and providers should address the widespread tendency for interpreters to omit details from their interpretations. This tendency might be remedied by training providers to deliver brief, clearly phrased utterances, and by teaching interpreters methods for remembering the number of key points in an utterance and for requesting clarification from providers when in doubt. Along with other studies, we agree that training interpreters and clinicians to address common patterns of alteration will markedly raise the quality of communication between providers and LEP patients13,29
Our findings should be interpreted in light of several limitations. First, although we included five interpreted languages, we recorded relatively few encounters and interpreters in each language, reducing our statistical power. Second, our inability to randomly assign interpreters, physicians, and patients to encounters may have a confounding effect on our calculation of alteration rates by language.
Third, our small sample size, combined with the lack of randomization, limits our ability to use a mixed-effects model to isolate interpreter effects from effects of topic, language, and provider/patient interaction. Nevertheless, we recorded 38 encounters, with a minimum of 5 encounters in each language except Mandarin. We therefore included Mandarin in our descriptive statistics, including the overall alteration rate, but removed it from comparative analyses, because only one interpreter participated in all three encounters.
Finally, all recorded encounters addressed a very restricted range of topics in an established continuity relationship. Our best case approach substantially underestimates the likely rate of alterations in more dynamic encounters—for example, those involving a new patient, a new diagnosis, or a new workup.
This study is significant for several reasons. First, our sample of interpreted encounters (38) is larger than in any previous investigation of interpreter alterations2,27,29,31,32
. Second, we included five different languages representing four distinct linguistic families. Thus, our finding that the rate of clinically significant alterations remains essentially stable across languages assumes a special importance.
Third, we introduced a methodological refinement to this area of inquiry by calculating rates of alteration per utterance per encounter, instead of per total number of encounters. While the latter approach pools diverse phrases, topics, interpreters, physicians, and patients, we argue that our approach restricts measured alterations to the basic triad of interpreter, physician, and patient, enabling us to better isolate the interpreter effect from other potential variables.
Finally, our study design enabled us to calculate a baseline alteration rate that avoids potential bias introduced by variations in interpreters’ training and experience or by emotionally charged provider/patient exchanges.
Like Pham and colleagues, we remain open to the possibility that interpreter alterations may clarify potentially faulty communication29
. Before designing interventions to improve interpreted encounters, it is advisable to establish baseline rates of alterations, both positive and negative, in key clinical settings: for example, end of life, new life-threatening diagnoses, and informed consent for major surgery. Such baseline variations in speech patterns, flagged by language and culture, can then be compared to rates of miscommunication in English-only encounters. This study represents a first step toward establishing such a baseline.