Birth order, family size, and children's use of physician services.

The purpose of this study is to separate out the effects of number of siblings and birth order on children's use of physician services. Prior research has consistently revealed an inverse relationship between family size and physician visits, but the possible confounding influence of the child's ordinal position in the family has been ignored. Later born children may be taken to the doctor less often than first and other early borns because of their parents' increasing knowledgeability in regard to child care as well as their growing understanding of the uses and limitations of physician visits. On the assumption that part of the family size effect observed in prior research may have been due to the clustering of first and early borns in small families, an inverse relationship between birth order and physician utilization is hypothesized. Support for this hypothesis comes from an empirical study of 1,665 children from 587 families in which variation in family size is statistically controlled.