Statistical analysis
Baseline characteristics of the population were described as the mean (+/- standard deviation) for quantitative variables and numbers (percentages) for qualitative variables. Quantitative and qualitative variables were analyzed by t-tests and chi2 tests, respectively. Two types of analysis were carried out (i) A multivariate analysis for factors associated with the probability of declaring a psychosocial difficulty at a consultation was conducted, considering mixed effects for longitudinal data. We defined at the second level the children. We defined at first level each consultation during which the psychosocial questionnaire was completed. Factors associated with a p-value <0.10 in the univariate analysis were considered in the multivariate logistic model. In this model, time was included as an independent variable. Additionally, subgroup analyses for children with blood disorders and CNS tumors were carried out (ii) We evaluated the probability of psychosocial difficulty over time by using Kaplan-Meier failure function curves. We completed a parametric survival regression model based on the same longitudinal data structure with two levels. The original date was the first consultation when the psychosocial follow-up began. However, we did not have the same follow-up duration and measurements’ time between patients according to their oncologic disease. Considering this, time to consultation was considered as an independent factor to assess the potential influence of the delay when the measurement is taking place.
All statistical analyses were performed with STATA software V14 and a p-value <0.05 was considered to denote statistical significance.
We defined the primary endpoint as the probability of presenting at a consultation with a learning difficulty at school. The secondary endpoint was to evaluate the probability of presenting a learning difficulty over time. Other psychosocial difficulties were also analyzed for further explorations.
This study was based on a database supported by the Commission Nationale de l’Informatique et des Libertés (CNIL) registered under the N° 912302.