Mantel-Haenszel analysis of Oxford data. I. Independent effects of several birth factors including fetal irradiation.
Data from the Oxford Survey of Childhood Cancers were subjected to the Mantel-Haenszel procedures to recognize independent effects of associated factors in retrospective data. Our results showed that several birth factors, including fetal irradiation, social class, maternal age, and sibship position, exerted separate effects on childhood cancers in general, and reticuloendothelial system neoplasms in particular.