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Southampton researchers look at why people choose not to take part in clinical trials

Clinical trials couldn’t take place without people volunteering to take part. All doctors depend on volunteers to better understand the safety and efficiency of new treatments – without them there could be almost no research.

However, researchers often struggle to recruit volunteers and over recent years there has been a overall decline in the number of people taking part in clinical trials.

Little is known about why people choose not to take part in research, even when approached by their doctor or nurse. Now, researchers from the NIHR Southampton Biomedical Research Centre have worked with almost 300 women to better understand the main barriers and reasons to not take part in pregnancy-related clinical trials.

Identifying the barriers to taking part

This latest study, published in the Social Science and Medicine journal, involved surveying 296 women who declined to participate in two Southampton pregnancy-related randomised controlled trials.

Both trials required pregnant women to take daily vitamin D tablets throughout their pregnancy to see if it had a positive effect on their and their baby’s health. They also had to attend two extra ultrasound appointments and the baby received a scan just after birth to measure bone mineral density. One study also involved a phone call during pregnancy from the research nurse and a home visit one month after birth.

Dr Strömmer and her team developed a questionnaire that asked women to give their reasons for not taking part in the trials. The list included ‘I don’t want to take pills during my pregnancy, I don’t want my baby or me to have a bone density scan, I am too busy, I don’t want to take part in any research’ as well as the opportunity to give free-text answers.

“Previous research has shown that of 122 clinical trials, covering 18 clinical areas, only 31 per cent had reached their target number,” explained Dr Sofia Strömmer, a psychologist based at the MRC Lifecourse Epidemiology Unit in Southampton.

“We want to understand the underlying reasons for people choosing not to participate in clinical trials – even relatively straightforward trials, such as our two vitamin D supplement studies – so we can look to address it.

“Studies that don’t get enough volunteers might not record enough results to show a benefit or detriment to using a new therapy. Only when research is tested fully, and on a representative cross section of society, can we get the best possible results to inform us,” Dr Strömmer continued.

A lack of trust

Overall, the study concluded that there is a lack of trust in those who chose not to take part in the clinical trials.

It identified that, despite what women were being told about the trial, those who declined to take part were worried that they or their baby could be at risk and felt that coming in for extra appointments wasn’t possible to fit into their lives.

This is compared to those who agreed to take part and believed that the research would cause no harm and were able to fit the appointments into their lives.

Breaking down barriers

Following the study, Dr Strömmer has developed number of recommendations to encourage more people to participate in clinical trials and improve participation rates.

Focussing on building trust, one recommendation is to set up a review-style platform for participants to provide feedback and rate their clinical trial experience.

“We hope that feedback and reviews from people who have taken part in clinical trials will give potential participants an independent source of information, rather than hearing from a doctor, nurse or researcher.

“Investing time in open and honest discussions around the risks and benefits of taking part in research, improving the visibility of research teams, and better advertising study safety and ethical conduct, are also key to building trust between potential participants and clinical teams.

“We believe these recommendations could be implemented relatively easily into our pregnancy trials and protocols, and could make a real difference in empowering and enabling women to feel heard and supported – and therefore raise participation rates in clinical trials,” Dr Strömmer concluded.


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