This blog is a follow-up from our webinar Foundations of Clinical Outcome Assessment Localization.

Clinical outcome assessments (COAs) play an increasingly central role in capturing how patients feel, function, and experience their condition or treatment. Yet as studies expand across more countries and populations, one issue consistently resurfaces:

A translated COA is not automatically conceptually equivalent and culturally appropriate.

Understanding the basics of COA localization, and with it, linguistic validation, is essential not only for teams new to globalizing patient data, but also for teams that want to ensure their processes still meet the expectations of regulators, patients, and modern study designs.

When we talk about COAs, we’re referring to the four types of instruments:

• Patient Reported Outcome (PRO)
• Observation Reported Outcome (ObsRO)
• Clinical Reported Outcome (ClinRO)
• Performance Reported Outcome (PerfO)

Why Standard Translation Is Tricky

Because COAs focus on how a patient feels, functions, or survives, a standard translation won’t yield the same level of conceptual equivalence and cultural appropriateness. For example, English native speakers understand the question, “How blue do you feel today?” However, when translating this into most other languages, the same phrase of “feeling blue” does not exist. That concept would have to be defined in English and then adapted into a phrase in the local language that has the same conceptual meaning. Similarly, a standard translation won’t achieve the same level of cultural awareness and appropriateness. A basic question about walking five city blocks may be standard and familiar for some populations, while others—such as more rural communities—may have no sense of what walking five city blocks feels like. In those cases, the question should be adapted to a concept that’s more suitable for that population. 

In the case of ClinROs, which are directed to clinicians and tend to have less colloquial and laymen phrasing, the more technical nature of the vocabulary and instruments requires a clinician to review the translation and ensure that correct medical terminology is used in each language. 

Regardless of the COA type, every COA item represents a concept that often isn’t best translated literally. Each question captures a specific idea that must remain consistent across languages and be adapted to fit the local culture. 

The Standardization of Localizing COAs & Introduction of Linguistic Validation 

Prior to 2005, there was no real consistency in COA localization. It was up to sponsors, CROs, copyright holders and developers, and language partners to ultimately decide how to translate these concepts across global markets. However, that all changed in 2005 when the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) first published the Principles of Good Practice for the Translation and Cultural Adaptation Process for Patient-Reported Outcomes (PRO) Measures.

This was the first time a set of guidelines established a unified, validated approach for translating questionnaires, known as linguistic validation. Now, the ISPOR guidelines are recognized across the industry and regulatory agencies as a best practice. Linguistic validation, which includes the following steps, is a more robust translation process that ensures both conceptual equivalence and cultural appropriateness:

• Concept definition
• Dual forward translation
• Reconciliation
• Back translation
• Resolution
• Cognitive debrief or clinician review (depending on the type of COA)
• Final documentation and QC

These steps ensure that additional language versions achieve conceptual equivalence and cultural appropriateness with respect to the English source, regardless of whether the English source was validated. This supports the collection of consistent data across languages.

Regulatory Expectations on Linguistic Validation

When COAs support either a primary or secondary endpoint in a study that will have a labeling claim (new drug application) or a label change, regulatory bodies look for evidence that:

• Translated concepts match the English source
• Patients understood the items as intended
• The methodology followed recognized standards

Foregoing linguistic validation can lead to questions from regulatory authorities that can be difficult to answer later. Attempting to linguistically validate after data has already been collected often reveals conceptual inconsistencies that cannot be corrected without changing the instrument translation, making the existing data unusable. This is why it’s imperative to discuss the established guidelines with your localization partner when translating COAs.

What About Electronic Clinical Outcome Assessments (eCOAs)?

With the introduction of eCOAs in the clinical space, the complexity involved in planning and preparing to launch studies has grown substantially. New considerations have emerged as these measures are deployed in digital formats, including:

• Does the digital platform handle non-English content correctly?
• Will text expansion impact layout or usability?
• How does the screenshot and in-context review workflow support each language and overall timelines?
• Are language rollouts synchronized with study milestones?

Strong alignment from the sponsor, CRO, eCOA vendor, and language services provider (LSP) is essential to avoid downstream bottlenecks.

What to Look for in a Localization Partner

Finding the right partner for COA localization goes beyond selecting a translation provider; it’s about choosing an extension of your own team. COAs touch endpoints, timelines, regulatory strategy, patient and site experience, and ultimately the credibility of your data. The partner you choose should be ready and built to handle that level of responsibility.

Here’s your checklist for finding the right partner:

• Dedicated linguistic validation workflows, resources, and SOPs
• COA-specific technology (not repurposed translation systems)
• Experienced cognitive debriefing and clinician networks
• eCOA migration expertise
• Global production capacity
• Regulatory fluency
• Innovation roadmaps that incorporate AI responsibly

In short, a strong COA partner connects science, language, technology, and regulatory strategy. 

Conclusion

While the fundamentals of COA localization haven’t changed in the past 20 years and continue to anchor the industry, trials are changing—and fast. With more clinical studies taking place overseas, and as technology continues to evolve and become more sophisticated, knowing the basics of localizing these instruments matters more than ever before.

It’s imperative to view linguistic validation not as an additional step in your localization process, but as the process that ensures every step that follows is compliant and accurate. When done well, linguistic validation protects the science, the data, and ultimately the patients. 

If you’d like support evaluating your COA strategy or planning an upcoming global trial, contact us today to get started.