Why paediatric trials struggle to recruit, and what is helping
Small populations, cautious parents and dozens of trials chasing the same patients make recruitment the most common reason paediatric programmes slip.
In brief
Small populations, competing trials and consent make paediatric trial recruitment hard. How research networks and family-centred design are helping.
Ask anyone running a paediatric development programme what keeps them up at night, and recruitment will be near the top. Paediatric studies routinely take longer to enrol than planned, and delays ripple through regulatory commitments.
The structural problems
Small populations. Many paediatric conditions are rare, and many common adult conditions are uncommon in children. The eligible pool is small to begin with.
Competition. Regulatory requirements mean that several companies developing drugs for the same adult condition may each need paediatric studies. They end up chasing the same few hundred children at the same handful of specialist centres.
Consent and assent. Parents or guardians give consent, and children old enough to understand are asked for their assent. Parents are understandably cautious about enrolling a child in an experimental study, particularly one with a placebo arm or frequent blood draws.
Burden. Trial visits, procedures and travel fall on families who are often already managing a child’s illness alongside work and other children.
What helps
Research networks have made a measurable difference. In Europe, the conect4children network, launched in 2018 as a public-private partnership, was set up to provide a shared infrastructure of trial sites and expertise across countries. The EMA coordinates a network of paediatric research networks, known as Enpr-EMA. In the US, the Pediatric Trials Network funded by the National Institutes of Health runs studies of off-patent medicines.
Design changes help too: fewer and smaller blood samples, using pharmacokinetic sampling from routine care, home visits and telemedicine, and avoiding placebo where an active comparator or extrapolation will do.
Involving families earlier
The most consistent advice from investigators is to ask families before the protocol is finalised. Patient and parent advisory groups catch burdens that look trivial on paper and decisive in a family’s week.
