Retention of participants is one of the biggest challenges in long-term clinical trials. Retention is a variable that’s difficult to control—and often overlooked.
Participant attrition can derail a study, impacting researchers’ careers and delaying scientific progress.
Studies indicate that the dropout rate in clinical trials can exceed 20%. For multilingual participants, the challenge is even greater.
Language barriers, cultural differences and misunderstandings about trial expectations can contribute to early withdrawal.
Researchers typically offer incentives, such as payment, to entice participants to stay on. However, financial constraints are just one of many reasons why participants drop out. In a recent study on participant experiences in multilingual trials, communication issues were found to be the #1 reason for dropping out. Logistical difficulties, such as distance to the study center, were just as important.
While researchers can’t control every variable in participants’ lives, there are steps they can take to improve retention and attract more participants.
How to Improve Participant Retention in Long-Term Clinical Trials
Enhancing retention in long-term clinical trials requires a multifaceted approach, particularly when working with multilingual participants.
The following are actionable strategies that can improve engagement and minimize dropout rates.
1. Provide Clearly Translated and Localized Trial Information
Researchers must ensure participants fully understand the trial requirements and procedures. Many participants drop out because they misunderstand the study’s expectations or the level of commitment required.
This isn’t just important for retention. It also plays a role in ethical compliance and data integrity.
To address this:
- Use plain language: Clinical trial documents should be written in clear, simple language that avoids jargon and complex terminology.
- Translate materials professionally: Poorly translated documents can lead to misinterpretations that deter participation. It’s critical to hire professional medical translators with expertise in clinical research.
- Localize materials for cultural relevance: Direct translation is not enough to earn participants’ long-term trust and commitment. Localization ensures that materials align with cultural expectations, regional sensitivities and literacy levels in target regions.
- Provide multilingual informed consent forms (ICFs): ICFs should be available in participants’ native languages and written in an easy-to-understand format. Participants should also have access to a point of contact, such as a helpline, where they can ask questions about ICFs in their native language.
2. Implement Linguistic Validation for Patient-Reported Outcomes
Patient-reported outcomes (PROs) are critical in many clinical trials. To maintain data integrity, patients across regions and language barriers must have the same clear understanding of what is required in these forms.
To address this, researchers must employ thorough linguistic validation of all translated materials. This is a service that ensures translated materials convey the same meaning as the original text.
This also impacts participant retention. If participants struggle to comprehend questionnaires due to poor translation, they may feel frustrated or uncertain about their responses. This confusion can lead to higher dropout rates.
Linguistic validation improves retention by ensuring that multilingual participants fully understand trial materials, particularly patient-reported outcomes (PROs).
Linguistic validation is required by regulatory bodies like the FDA, EMA and ISPOR. However, there are no standards for how to undertake it.
Responsible linguistic validation includes, at a minimum:
- Forward and back translation: Documents are translated into the target language and then translated back into the original language to check for consistency.
- Cognitive debriefing: Testing translated materials with a sample of the target population to ensure comprehension and cultural appropriateness.
- Expert review: Medical and linguistic experts review translations for accuracy and clinical relevance.
3. Prioritize Communication Throughout the Trial
Ongoing communication is key to keeping participants engaged. A prolonged lack of interaction between study visits can lead to lost interest, or participants may simply forget to take the necessary steps.
One simple strategy for improving communication is to ask for multiple forms of contact. Research has found that many participants are lost due to the researcher’s inability to follow up. When a participant moves or changes their phone number, they become unreachable.
Additional strategies include:
- Multilingual study coordinators: Employing staff who speak participants’ native languages helps bridge communication gaps and builds trust.
- Participant newsletters: Providing updates on the study’s progress, findings, or patient stories can reinforce the importance of their participation and maintain engagement.
- 24/7 support helplines: Offering multilingual helplines allows participants to ask questions and resolve concerns at any time.
4. Reduce the Burden of Participation
Retention rates improve when trial participation is as convenient as possible. Many participants leave studies due to logistical difficulties such as travel time, costs, or family responsibilities.
Ways to reduce participant burden include:
- Decentralized or hybrid trial models: Allowing participants to complete some trial procedures remotely, such as telemedicine consultations or at-home sample collection, can reduce travel stress.
- Transportation and reimbursement support: Offering travel assistance, ride-sharing services, or reimbursement for travel expenses can make participation more feasible.
- Flexible scheduling: Accommodating participants’ availability by offering evening or weekend appointments helps minimize disruption to their daily lives.
- Caregiver involvement: Providing information and support to caregivers ensures they can assist participants throughout the study, improving adherence.
Wolfestone Group: Improve Communication and Retention with Clinical Trial Language Services
Retention of multilingual participants in clinical trials is a challenge, but researchers have the power to significantly reduce drop-outs. A few simple strategies have proven effective at keeping participants engaged in the long term.
Many of these strategies center around communication. Speaking to participants in their native language helps build trust, while adapting materials to their literacy levels and cultural customs ensures understanding and accurate reporting.
Even small gestures, like sending a translated newsletter with study updates, can keep participants engaged and reinforce their commitment to the trial.
Researchers specialize in their areas of study, but effective global communication requires a different expertise. At Wolfestone Group, we provide the professional translation and localization needed to keep your trial participants engaged.
Wolfestone Group specializes in high-quality medical translations and language support for clinical trials, including linguistic validation. For over two decades, we’ve helped researchers develop accurate, compliant and patient-centered trial communications in 220+ language pairs.
Linguistic support can make or break a multilingual clinical trial. Don’t risk an attrition rate of 20% or more due to poor communication.
Schedule your free consultation now to learn more about how Wolfestone Group’s clinical trial linguists can manage global communication and improve retention in your clinical trials.
