Study population
From a total of 21,205 patients aged 0-17 who were diagnosed with
cancer, we applied a 1-year washout period to identify and include newly
diagnosed cancer patients for the study. To obtain socioeconomic status,
we extrapolated insurance payment data from the patient’s parent income
data and linked the two parameters together. We excluded 5,598 patients
who lacked parent data. Our study design also excluded cancer patients
that died within 5 years of diagnosis. Finally, we excluded 150 patients
whose medical expenditure was in the upper and lower 1% of all medical
costs. A total of 7,317 patients were ultimately used for the study.