Internet Explorer is no longer supported by Microsoft. To browse the NIHR site please use a modern, secure browser like Google Chrome, Mozilla Firefox, or Microsoft Edge.

PRCs achieve an average 95% patient retention rate in Moderna vaccine trial

Learn how Patient Recruitment Centres prioritise the participants’ experience to support excellent patient retention rates.

Published: 09 August 2023

The retention challenge

Patient retention is one of the biggest challenges for clinical trials globally, yet fundamental to a trial’s success. Lower than expected retention rates can affect study validity, use up valuable research resources and slow the discovery of new treatments. More importantly, it calls into question the quality of the participant’s experience. Discover how the NIHR Patient Recruitment Centres maintained high retention rates in a recent large scale, late-phase vaccine trial.

Patient retention in a clinical trial is defined as the strategy and tactics designed to keep participants enrolled, and prevent them from discontinuing participation i.e. dropping out (National Library of Medicine).

In February 2022 Moderna opened a COVID19 vaccine booster trial in the UK - a phase 3 study to compare the immunogenicity and safety of two mRNA vaccine variations. By the time the study closed 27 sites had recruited participants, three of which were PRC sites.

In total, the PRCs recruited 378 participants to the trial which is now in follow-up. As of March 2023 the PRC average patient retention rate is 95%, an impressive achievement when compared to average clinical trial retention figures which vary across sources with 88% being the top end of the scale (BMJ).

So what strategies and tactics did the PRCs use? What is their secret to retaining participants?

Patient-centred approach

Predominantly it’s about taking a patient-centred approach.

Juggling work and life commitments can be a huge ask for participants taking part in traditional site-based trials. Not only do these demands contribute to high patient drop-out rates, the level of commitment required often discourages patients from joining studies in the first place.

The PRCs aim to minimise the burden of participation and improve the participant experience, wherever possible, across all the trials they support. For example, by offering appointments outside of work hours to suit the participants schedule, and providing welcoming waiting areas with free refreshments and parking. Providing a concierge style service for all participants is part of the PRCs remit.

Communication is key

Another factor that can significantly impact retention rates is communication. Effective communication between site staff and patients can minimise missed appointments and ensure participants are clear on what is required from them from the outset.

For example, for the Moderna trial, this included asking participants about their communication preferences, whether that was email, phone or text. This enabled timely provision of information about the study and what each appointment would involve. For all studies participants are given a welcome pack with relevant contact information, including the main Principal Investigator’s team.

Beyond the more formal communication, the softer communication skills, abilities and efforts of the study team can also influence retention. It’s crucial to allow sufficient time, and create the right environment for conversations to take place, for patients to ask questions and generally feel confident about participation.

Both aspects of communication are important to retention and should not be underestimated, according to Helen Quinn, Clinical Director, PRC: Exeter said:

“We have worked hard to ensure that patients are at the forefront of the research we deliver. Appointments are scheduled around the availability of the patient where possible. Reminders are sent out via their preferred contact method, e.g. SMS to reduce the amount of missed appointments.

“When consenting patients we ensure the appointments allow quality time to give patients a chance to raise concerns, understand the process of the study and begin to build a relationship with our team of research nurses. We make sure to update participants about any changes or amendments that have occurred in the trial.”

During the trial it was important for patients to be able to reach the research delivery team quickly if they experienced COVID-19 symptoms - to allow for PCR tests to be completed within a certain time frame, a vital aspect to study. To ensure there was easy and rapid communication between participants and the site team there was a dedicated mobile phone for participants to contact research nurses on. Not only was this used during site open times, but was taken home with staff on weekends - this was particularly helpful during extended holidays, such as the Queen's Platinum Jubilee in 2022 when the main clinic was shut for four days.

Jane Wilson, participant on the trial shares her opinion:

“Being part of the Moderna trial was a very positive experience. I felt very valued for taking part in the trial and I was very pleased to be able to be a part of vital research into new vaccines. Everything was explained to me thoroughly and clearly at the outset and I was very aware of what was involved.

"On every visit to the PRC I was treated with great care by all members of staff. I was always greeted by name and significant care and attention was paid to how I was feeling and making me comfortable.

"The team made sure it was easy and convenient for me to take part in the study. Sending me reminders by email to complete my weekly symptom diaries and whatsapp messages with appointment reminders, for whenever I needed to come into the clinic. And parking and travel were all paid for by the trial. It was all very straightforward.”

Experience and expertise

For participants like Jane Wilson, the conversations they have with the site team will have a strong bearing on their overall trial experience, and consequently their likelihood of staying in the trial. As well as having the correct communication channels and skills, it is important that the patient-facing team is experienced and knowledgeable in delivering commercial research - which can often be more demanding on staff.

Because the PRCs only deliver commercial trials,they have vast experience in this area and ensure any new team members are upskilled from the outset. The involvement of experienced staff contributes to good participant communication; from translating the protocol into patient-friendly language, to having an acute awareness of the participants' end to end research journey, and everything it involves.

Remote trial capabilities

Another aspect of the PRC’s patient centred approach is their readiness to offer home visits if participants are struggling to come into the clinic, for example, due to mobility or transport issues. This inclusive approach is a capability that all PRCs are currently expanding, sometimes in conjunction with companies that specialise in providing home-care services.

Joanne Jones, Clinical Research Nurse, describes how PRC: Exeter incorporated home visits for the Moderna trial…..

“We had a number of participants who were unable to attend the clinic during parts of the trial for a variety of reasons; such as being unable to travel to the clinic or being symptomatic of COVID-19. We overcame this challenge by sending research nurses to participants' homes if they had symptoms of covid or had had close contact with someone who had covid. This meant that our research nurses could collect vital swabs needed for the trial, but it also provided an opportunity to perform extra checks on the participants if necessary, such as testing their blood oxygen levels - important in COVID-19 symptomatic patients. Tests such as these can either offer peace of mind to the patient and/or allow the patients to seek extra medical care if needed, which is reassuring for patients to have a nurse on hand to advise them on this.”

Jane Wilson, contracted COVID-19 during the study:

“I actually did develop COVID-19 during the trial. I called the PRC and told them I had tested positive for COVID-19 and within an hour there was a nurse on my doorstep in full PPE (personal protective equipment) ready to take the necessary swabs on my doorstep. I was so impressed with how swiftly they acted and the reassurance of seeing someone face to face.”

Patient Experience

Patient experience is paramount at the PRCs. For the Moderna vaccine trial, the site allowed participants to bring their carer or partner with them to any follow up visits. This is not always possible at research sites, especially in a clinical environment when COVID precautions were still a concern. However, the PRCs have dedicated facilities affording them the space to offer this opportunity, separate from hospital clinics. Allowing participants to bring their carer or partner can provide them with extra reassurance and a more positive experience.

Every PRC provides the opportunity for participants to feedback on their experience during their clinical trial via the Participation in Research Experience Survey (PRES). The survey is issued to all participants for every study run in the PRCs. This is a chance for participants to share their experiences of taking part in clinical research. This feedback is then collated and analysed and is used to help improve the way research is delivered and make improvements for future participants. PRES is an extremely valuable tool to ensure participant experience is at the heart of research delivery.

An example of PRES feedback from a participant at PRC: Bradford:

“Very clear information and everyone made it an enjoyable experience from arrival to departure.”

Overall, 97% of participants surveyed at our centres said they would take part in commercial research again (annual figures from Participant in Research Experience Survey 2022/23).

Patient retention in clinical trials is an essential challenge for site delivery teams and sponsors globally. Poor retention rates can affect study validity, be costly and slow the discovery of new treatments and therapies and also be an indicator of poor patient experience. Every trial is different, testing different treatments, in different settings on a variety of participants. To ensure consistently high participant retention rates delivery methods and participant interaction will differ from study to study. Participant retention must utilise a continuous improvement ethos, combined with a patient-centred approach. This is something the PRCs try to implement; mandatory implementation of PRES to evolve delivery, patient-centric behaviours, excellent participant communication and highly skilled staff. A 95% patient retention rate for a vaccine trial is momentous, but one the PRCs believe can be replicated in many more of their studies.

Further information

Latest case studies