Hospitalization of medicaid children: Analysis of small area variations in admission rates

Population-based hospitalization rates were computed and analyzed for AFDC children among 14 small area subdivisions of the State of Washington. Medical-surgical admission rates ranged from 65.3 to 161.7 per 1,000 person-years among the 14 areas. Surgical admission rates were significantly higher in urban areas; medical admission rates were significantly higher in rural areas. The majority of variance in overall rates was accounted for by admissions for four diagnostic categories: gastroenteritis (18-fold differences), lower respiratory infections (15-fold differences), upper respiratory infections (8-fold differences), and ear, nose, and throat (ENT) surgery (6-fold differences). Secondary analysis indicates that these differences in admission rates wre not associated with: medical need or demographic factors, epidemic patterns of disease, physician supply, hospital bed supply or occupancy rates, or severity of disease or delay in seeking medical care as reflected by average length of stay. It is possible that the observed variations may reflect either differences in the propensity of local physicians to hospitalize or differences in the use or adequacy of community, ambulatory, and preventive care.