Language services are an essential component of diverse and inclusive trials. Through linguistic validation, trials can ensure accurate and conceptually equivalent documents that are comparable across target languages, cultures and countries. Here we outline key success factors in the linguistic validation process.


As clinical trials grow and globalise, they become increasingly complex and include patients from a broader spectrum of cultural, linguistic and literacy demographics. With this increase in scope, scale and reach, language services are imperative for study and trial designs. The translation of key study documents on the trial’s critical path, like Clinical Outcome Assessments (COAs), is instrumental to the good conduct of the trial and the collection of reliable data. Linguistic validation goes beyond simple translation services to ensure conceptual equivalency. This equivalency facilitates accurate representations of trial data essential to evaluating the efficacy of the trial, treatments and overall patient experience. In this article, we discuss the importance of linguistic validation (LV) for COA translations, touch on the LV process and services and offer insights on key factors for success based on our extensive experience in language services.

Linguistic validation for COA translations

COAs are the primary tool through which studies assess patients’ quality of life. COAs include a range of documentation – PROs, ClinROs, ObsROs, PerfOs – and provide insights into the validity of the trial and the patient experience. For the information captured in COAs to be useful, the critical data from these documents must be accurately collected and comparable across languages, cultures and countries. Simple translation methods are insufficient to guarantee the conceptual equivalency necessary to ensure the accuracy of documents translated into target languages. Linguistic validation, a rigorous translation process, ensures that COAs accurately represent the increasingly diverse and complex patient and trial data that is key to evaluating the efficacy of the trial and overall patient experience.

Linguistic validation services for COAs can include:

  • Patient Reported Outcomes (PROs) including ePRO
  • Clinician Reported Outcomes (ClinROs)
  • Functional assessments
  • Cognitive tests
  • Review of eCOA screenshots
  • Cognitive debriefing interviews
  • IVRS prompt recording and system testing

Linguistic validation process         

Through the strict LV process, translations become credible, conceptually equivalent documents that are linguistically and culturally valid to the target population. For professionals and companies involved in global clinical trials, LV is critical for two core purposes: patient centricity and data accuracy. As an element of patient centricity, LV localises COAs and other documentation to align with the target population's language, literacy and cultural specificities. This alignment provides more equitable access for patients and enables more inclusive trials. The validation process similarly ensures that translated documents provide accurate, comparable data that can generate insights to inform trial considerations.

Key success factors for linguistic validation

As the author of the Linguistic Validation Manual for Health Outcome Assessments, with a specialty in cross-cultural adaptation, ICON recognizes the following as a few of the key factors for successful linguistic validation:

List of concepts

Conceptual equivalence is the most important equivalency measured in the linguistic validation process. A clear and concise list of concepts, established with the help of the instrument developers, serves as a point of reference during the translation process. Trained linguists test the equivalency during the forward- and reverse-translation phases to ensure key concepts remain clear and relevant. By establishing an agreed list of concepts before translation, the study team guarantees a consistent understanding of the source instrument items resulting in target-language documents that carry equivalent concepts.   

In-country linguist network

A strong in-country network of linguists trained on the specifics of linguistic validation methodology helps to ensure fast and efficient scalability. With more linguists trained in LV within the target country, it is easier to complete rare language combinations that may only exist within that target country. A stable network will enable faster trial startups by accomplishing the frontload of the linguistic validation processes earlier and facilitating faster patient recruitment. During the cognitive debriefing step in the linguistic validation process, the LV specialist is responsible for recruiting suitable respondents that meet the study criteria. Cultivating and maintaining this network leverages local knowledge and encourages specialists to invest time and effort into their patients’ network of care.

Experienced specialist staff

In an increasingly competitive hiring market, an experienced specialist staff is invaluable. For timely and accurate validation, sponsors need efficient, seasoned personnel who can support the different components and stakeholders involved in the LV process including sponsors, developers, project managers, e-providers to cover technological aspects and others. Qualified specialists can provide extensive knowledge of local regulations and healthcare practices to help navigate the process smoothly and effectively.

Robust technology

Leveraging advanced technology with an efficient translation management system and Computer Aided Translation (CAT) tool will help streamline the translation process. The proper CAT tool quickly identifies repetitions within the translated instrument, offers auto-propagation of a translation segment and provides automatically managed quality checks to ensure precision. Investing in a robust CAT tool means added benefits for the LV process including automated features that reduce human-input workload, reduced risk and quality assurance. These technological abilities are especially important when considering large-scale translation services for programs, eCOA migration and implementation or the inclusion of Interactive Voice Response (IVR) Systems.


As clinical trials globalise, patient diversity and inclusion expand and trial designs and technologies continue to advance rapidly, it is more important than ever to ensure effective validation of COAs. We understand the complexity and dynamic challenges associated with linguistic validation and have outlined the above factors as key elements of success in the process.