What a bad translation costs

Poor medical translation can harm patients, trigger recalls and repeat procedures, obstruct understanding and undermine trust. Its consequences depend on both the error and the processes that allow it to reach readers.

Patient harm and recalls

Medical texts need to be error-free because mistakes can cause serious harm or death. ¹ Readability and unequivocal meaning matter because confusing texts can mislead. ¹

In 2004, Mead Johnson Nutritionals recalled two infant-formula products after preparation instructions were mistranslated from English into Spanish. ¹ The FDA warned that preparation following the Spanish instructions could cause seizures, irregular heartbeat, renal failure and death. ¹

In Berlin, forty-seven patients with knee replacements in 2006–2007 received prostheses without the required bone cement after staff understood “non-modular cemented” as not requiring cementing. ^{1, 2} A 2012 account reported re-operations, explaining that staff had shelved the devices with cement-free prostheses and the error was noticed only when German-language stickers appeared on the outer cartons. ¹

The accounts disagree about the instructions supplied with the device. ^{1, 2} The 2012 account says there were no German instructions for use. ¹ A 2024 retelling says German instructions were inside the package but the outside label remained English, describing a legal requirement covering instructions but not labelling. ²

Frequency and hidden errors

A 2007 literature review identified forty-four articles on translating clinical and medical-research documents; ten described error types, most often inability to achieve cultural equivalence and oversimplification of crucial information. ¹ The reviewed papers did not establish error frequency, and many concerned interpreting rather than written translation. ¹ A 2012 account also reported no available statistics on how often translation errors cause harm. ¹

Errors caught during review need not produce harm. ¹ In one centrally authorised product’s German summary of product characteristics, a subcutaneous injection was repeatedly described with einnehmen, suggesting swallowing or oral administration, instead of wording meaning administration or injection. ¹ The coordinator caught the error in review despite the specialist provider reportedly using expert translators and rigorous quality assurance. ¹ Errors may also remain unnoticed because readers mentally repair equivocal or incorrect wording to match what they know or think it means. ¹

Sources of failure

The few published reports make an error’s precise origin difficult to determine. ¹ Intrinsic factors include insufficient language proficiency or medical knowledge and oversight by experienced translators, which is difficult to eliminate completely. ¹ Even an inadvertently misplaced comma can have disastrous consequences in medicine. ¹ Extrinsic factors include manufacturers or marketers overlooking the need for native-language documents and providing no translation, inadequate time or resources for translators, and other process shortcomings that prevent proficient translators delivering good work. ¹

Regulatory and review consequences

Unclear writing may be less persuasive, become unethical when it confuses or misleads, or delay a medicine’s marketing authorisation. ³ In a 2009 FDA conversation with a vaccine applicant, the agency requested standard operating procedures within two to three weeks; the company said English translations should be available within several days. ³ The call record noted apparent translation errors and unclearly written instructions. ³

In a sample of one hundred Spanish research-ethics-committee review letters reported in 2015, almost one-third of objections to participant information and consent forms could be related to translation from English. ⁴ Committees criticised excessive length and density, awkward, confusing or cumbersome style, and terminological and cultural pitfalls; detailed examination connected many issues with poor and often literal translation. ⁴

Spanish experts cited in 2015 also complained that poor English-to-Spanish translations by people lacking clinical experience forced ethics committees to review and rewrite information sheets. ⁵ They described literal consent documents as too long and technical for patients to understand. ⁵

Credibility

Even without being wrong or misleading, awkward language, sloppy writing or departure from the genre’s style can undermine the source author’s credibility and make readers question the underlying research’s quality. ^{1, 6}