Achieving Accuracy and Cultural Relevance Through Linguistic Validation
Clinical trials are a critical part of developing new treatments. For a drug, device, or diagnostic tool to be considered safe and effective, it must undergo thorough research on its effect on human health outcomes.
How to measure if a new treatment is effective? Clinical outcome assessments (COAs) are often used for primary or secondary endpoint evaluation. These are questionnaires designed to understand how a patient feels, functions, or survives.
Since clinical trials are often conducted within a demographically diverse population or across different countries, the questionnaires must be translated. In order to make sure the data collected based on the questionnaires are valid, it needs to be translated accurately and validated to be culturally relevant. This way, the subjects participating in the trials fully understand and can relate to the questions and answers.
An inaccurate translation could put the clinical trial at risk. Therefore, instruments must go through linguistic validation, considered the most rigorous translation process in the language services industry.
Translation and Adaptation of Outcomes Measures
Unlike other translation work that is more straightforward, linguistic validation requires forward and backward translations, as well as Clinician Review and/or Cognitive Debriefing. It entails simultaneous translations of independent translators and reconciliation of those translations. However, it is not just translating the instrument. It also involves cross-cultural adaptation and validation.
Linguistic validation is recommended for all types of COAs, and especially patient-reported outcomes (PROs). These instruments include instructions, questions, and response categories or response options. They should be easy to understand correctly for the participating subjects. Any ambiguity or inaccuracy could invalidate the clinical research trial data.
In practice, however, linguistic validation is often an afterthought in clinical trials. The quality and approach to linguistic validation widely differ. This disparity was revealed in a review of methodological studies on the translation and validation of instruments for cross-cultural research.
The International Society for Pharmacoeconomics and Outcomes Research (ISPOR), a global nonprofit professional organization in pharmacoeconomics and outcomes research, provides comprehensive guidelines for linguistic validation.
The framework includes the following steps:
Step 1: Translatability Assessment/Concept Elaboration
Before starting any linguistic validation process, a translatability assessment is performed to detect ambiguities in the source and to foresee issues that may occur during the localization of source text into another language. Based on the findings, a discussion with the client may be initiated to obtain suitable alternatives and options for ambiguous wording and phrases if needed.
Step 2: Dual Forward Translation
Two translators will independently translate the source content into the target language, producing two translated versions.
Step 3: Reconciliation
An independent linguist analyzes the two translations against the original and decides the best translation, either choosing one of the options or composing a new one.
Step 4: Editing
A fourth linguist edits the reconciled version, ensures it mirrors the source and is globally consistent and error‑free.
Step 5: Back Translation
The reconciled translation is then back-translated into the original source language.
Step 6: Equivalency Stage
At this stage, the back translation is compared to the original source to identify discrepancies. Based on the findings, the forward translation team and the back translation team will ensure to correct any mistranslations, omissions, and additions that impact the originally intended meaning of the source to produce the finalized version for linguistic validation.
Step 7: Linguistic Validation via Clinician Review and/or Cognitive Debriefing
Clinician Review
The finalized translation from step 6 will be reviewed by an in‑country clinician who is an expert on the study’s therapeutic area. In a report, the clinician will detail proposed changes and/or clarifications for consideration.
Cognitive Debriefing
Focus group is the most common way of performing cognitive debriefing. To perform cognitive debriefing with focus group, a small group of individuals (preferably from different educational and social backgrounds) from the target country is asked to evaluate the translated document based on their own education level or backgrounds. The cognitive debriefing can also be performed in a one-to-one setting if preferred.
Step 8: Final Translation Revision
The forward and back translation teams will revise the translation based on findings identified in the clinician review report and/or cognitive debriefing report. The Quality Control team will finalize the translation and ensure the translation layout mirrors the source.
Cultural Equivalence of Validated Instruments
Translations of COAs should be both conceptually and culturally equivalent. Not only should the meaning be equivalent across translations, but also the gathered data for each translation. This means the questions and response options have the same construct value across languages.
For example, a question about eating with a spoon and fork may not be relevant in a culture that predominantly uses chopsticks. A response option that includes eating pork will not apply in a country where it is religiously inappropriate to consume such meat.
The instruments should be adapted to each culture and target country, using equivalent values to make the data reliable and valid. This is the only way to aggregate and properly compare global data sets.
Linguistic Validation Services
Linguistic validation is a complex and time-consuming process. Therefore, it is advisable to delegate the translation and validation work to a specialized language services provider.
Welocalize Life Sciences deploys a linguistic validation process that meets the requirements of relative regulations and follows the ISPOR guidelines. In addition, we have also established workflows following the PROMIS methodology, a more complex process to validate scales.
