VersKiK: Study protocol of an observational registry-based study on the current state of follow-up care and adherence to follow-up guidelines after cancer in childhood or adolescence.

Background: This article describes the study design of the quantitative part of the VersKiK study, The primary objectives of this study are to examine the occurrence of late effects in survivors of childhood or adolescent cancer (module 1), investigate health-related vulnerabilities and medical service utilization within this survivor group (modules 1 and 3), and assess the alignment between documented follow-up care for cardiological and audiological late effects with guideline recommendations, along with evaluating the extent of adherence among paediatric cancer survivors (module 3).

Methods: This is a non-interventional retrospective observational cohort study. It is based on stochastically linked insurance claims data from approximately 150,000 statutory insured persons with information concerning around 25,000-30,000 cancer survivors recorded in the German Childhood Cancer Register (GCCR). To explore adherence to selected follow-up guidelines, intention to treat treatment data from clinical study groups for particular diagnostic entities will be additionally included.

Discussion: The growing group of survivors after cancer in childhood and adolescence is representing a special population with an increasing demand for life-long healthcare services through relative high probability of late effects. Currently, there is a limited evidence in Germany on utilization of corresponding medical services and adherence to follow-up guidelines. With this study design, we are aiming to address these gaps and, consequently, suggest improvements to existing follow-up guidelines and follow-up care provision in Germany.