[Barriers for including sufficient participants in multi-center drug research]

The SPACe 2: STAR trial is a multicenter trial in children with an autism spectrum disorder, divided over nine centers in the Netherlands. However, it is challenging to include enough participants due to various factors, including the varying status of the disorder and willingness of parents and children.

To identify and overcome the bottlenecks for practitioners during the trial to prevent major delays.

Online questionnaire with four multiple choice questions and six open questions to 70 practitioners from nine participating centers within the SPACe 2: STAR trial.

The total amount of respondents was 31 (44%). Practitioners frequently experienced adequate visibility and guidance by the researchers (42%). The primary reasons for physicians for not including patients were: no permission from parents (32%), forgetfulness regarding the study (32%), and fear of injections (16%). Respondents expressed a need for regular reminders (13%), extra promotion materials (23%), and more frequent presence of researchers during meetings.

Problems with inclusion can delay 45% of research. Practitioners are crucial: regular contact and timely problem solving promote inclusion. In addition, a schematic overview with interventions and the course of the study can simplify inclusion.