This research investigated factors affecting children's health, based on empirical analyses of data from Washington, D.C. and national data. By most measures, poor children experience disproportionate morbidity and mortality. Yet certain ear and vision problems exhibit a U-shaped relation to family income in both national statistics and the Washington sample. Analyses of this relation suggested crowded housing and limited access to care as possible causes of higher prevalences among poor children in the study sample; mechanisms for the affluent were unclear. Additional analyses identified various economic factors underlying apparent racial differences in children's anemia. Focusing on ambulatory care, the research found different patterns of health outcomes and service utilization across practice settings. Thus, although lower utilization seemed detrimental to poor children's health overall, utilization levels across settings evidently had less to do with these health outcomes than did other provider or system features. Finally, both national and study data revealed persisting inequalities in measures of utilization and barriers to access. In the study sample, the most significant barriers appeared to be low income practices, high provider charges, and absence of Medicaid. Findings suggest that current policy trends may exacerbate present deficiencies in illness prevention and early diagnosis among the disadvantaged. (Author)