2.3 | Statistical analysis
Descriptive statistics were generated to describe demographic, disease
characteristics, and treatment variables to compare the distributions
between patients treated at pediatric versus adult cancer centers, using
chi-square tests for categorical variables and tātests or Kruskal-Wallis
tests for continuous variables.
Kaplan-Meier survival analysis was performed to determine EFS. The
log-rank test was used to compare survival between groups. Univariate
and multivariable Cox proportional hazard (PH) survival analyses were
performed to identify factors associated with EFS. Cox PH survival
analysis results were presented as hazard ratios (HR) with 95%
confidence intervals (CI). Variables that had a p-value less than 0.1 in
univariate analysis were included in multivariable analysis. Prognostic
factors previously reported in the literature (LOC, primary site, and
sex in OGS and LOC and primary site in EWS) were included a
priori in multivariable analysis.
All analyses were performed using SAS (Enterprise Guide) statistical
software for Unix environment, version 9.4 (SAS Institute Inc, Cary, NC,
USA). Statistical significance was defined as p-value less than 0.05.
All data are reported as per the Strengthening the Reporting of
Observational Studies in Epidemiology (STROBE) guideline
(Appendix 2 ).