Socio-Economic Status and Childhood Leukemia in California

Abstract

Objective: To investigate the association between individual- and community-level socio-economic status (SES) and childhood leukemia, particularly its subtypes: acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Study design: We conducted a large case-control registry-based study in California. Methods: Information on 5788 cases and 5788 controls was obtained by linking California cancer and birth registries. We evaluated relative risk of childhood leukemia by community- (census-based) and individual-level SES measures (parental education and source of payment for delivery) using conditional logistic regression. Results: Children in higher census-based SES categories had a tendency toward slightly decreased risk of total childhood leukemia and ALL compared to children of the lowest SES. Compared to < 12 years of school, 13 and more years of parental education were associated with slightly decreased risk of total childhood leukemia, ALL and AML; however, confidence intervals were imprecise. Source of payment for delivery was not associated with either childhood leukemia nor with its subtypes. Conclusion: We found little evidence to support the suggestion that SES is associated with risk of childhood leukemia or either major subtype. It is likely that results of many previous studies that found an association between childhood leukemia and SES were influenced by selection or ecological bias.