Role of Incentives in Long-term Nutritional and Growth Studies in Children

Available published advice on use of incentives is limited and generally refers to short-term studies without longer follow-up, predominantly conducted in developed countries. We aim to summarize published information related to the use of incentives in long-term nutrition studies involving infants, children, and adolescents and the views of researchers in the field, to provide guidance on acceptable incentives. We conducted a literature review and a short online survey of researchers regarding their opinions on the use of incentives in paediatric long-term (follow-up) clinical studies. Responses from 38 researchers from 14 different countries indicated that 41% had used incentives to increase participation and 29% to 73%, depending on child's age and type of procedure, thought incentives may be used to increase compliance with follow-up visits. A small number of respondents thought incentives would not be approved by national ethics boards. Based on the literature review and the survey results, and European Society for Paediatric Gastroenterology, Hepatology and Nutrition working group concluded that incentives for children and adolescents up to the value of 30 Euros, based on average EU income levels, may be offered as cash, vouchers, or age-appropriate gifts or toys, in addition to reimbursing expenses. Additional incentives may be offered if a study includes more burdening procedures, techniques that may appear frightening for younger children, or requires sustained participation (eg, dietary diaries or activity monitoring). There was agreement that it is preferable to give toys or gifts rather than money to younger children.