Data Processing and Statistical Analysis
We screened data for duplicates, missing information, implausible and
outlying values, and insufficient detail. In these cases, we contacted
the local hospital representative to provide the requested information.
Only completed questionnaires were analyzed. We grouped the
participating countries as northern Europe (Denmark and Sweden), eastern
Europe (Poland), central Europe (Austria, Belgium, Germany, France,
Switzerland, the Netherlands), southern Europe (Italy, Spain) and the UK
based on previous publications on European pediatric oncology
patients.1
Continuous variables were displayed as medians with interquartile ranges
(IQRs). Categorical variables were displayed as frequencies (%). Due to
the low numbers, no statistical comparisons were made.