Rebecca Stellato

Longitudinal Studies in Pediatrie Gastrointestinal Surgery: Theory and Practice

Samenvatting

This thesis describes the current state of longitudinal data analysis in the pediatric gastrointestinal surgical literature. Many scientific articles describe operations in small groups of children, and it is crucial that these studies – performed in a vulnerable population – are carefully designed, analyzed, and reported. To identify methodological problems in long-term studies on gastrointestinal surgery in children, a literature review was performed on all scientific articles reporting on such studies in the years 2010-2019. More than half of these studies did not make efficient use of the longitudinal design. In the majority of articles that did report on repeated measures, we saw inefficient, inappropriate, or incorrect analysis of the longitudinal measures. Using a computer simulation, we tried to give insight into the consequences of this problem. In addition, the effects of two operations are described: anti-reflux surgery in children with severe gastrointestinal reflux that does not respond to medication; and gastrostomy placement for children with severe feeding difficulties. Children were followed over time and their symptoms and quality of life were registered. The study design and analysis were done in concordance with the current insights on evidence-based surgery.