N Total sample size
n Sub-sample size
χ2 Chi square
P P-value
Leukemia/lymphoma leukemia or lymphoma (ICD-9 codes: 200-202 and 204-8)
Brain and orbital tumors brain and orbital tumors (ICD-9 codes: 190-192);
Solid extracranial tumors Solid extracranial tumors include: cancers of the oropharynx (ICD-9 codes: 140-149); gastrointestinal cancers (ICD-9 codes: 150-159, 235); thoracic cancers (ICD-9 codes: 160-165); sarcomas (ICD-9 codes: 170-171); skin cancers (ICD-9 codes: 172-3, 176); breast cancers (ICD-9 codes: 174-5); endocrine and neuroendocrine cancers (ICD-9 codes: 193-4, 209, 237); and other (ICD-9 codes: 195, 199, 238, 239).
Rurality Rurality according to rural-urban distinction of the Federal Office of Rural Health Policy
Low-income communities Communities where median household income level was less than $50,000 were classified as “low income” and otherwise as “high income.”