Objective: To examine relations between characteristics of a child's u
sual source of primary care and involvement of that source before and
during hospitalization. Design: Medical record review of pediatric hos
pitalizations. Setting: All hospitals in Boston, Mass; New Haven, Conn
; and Rochester, NY admitting children during the calendar years 1988
through 1990. Patients: The study included 1875 randomly selected pedi
atric hospitalizations for five diagnostic groups tie, asthma and othe
r lower respiratory tract disease, abdominal pain [including appendici
tis], meningitis [bacterial and viral], toxic ingestions, and head inj
ury). Hospital records selected were limited to children aged between
1 month and 12 years and residing in the three study communities. Outc
ome Measures: Whether the primary care source examined the child befor
e admission to the hospital, referred the child to the emergency depar
tment, or served as the in-hospital attending physician. Results: Of t
he medical charts reviewed, 85.7% identified primary care sources. Chi
ldren in Rochester had higher rates of medical visits before admission
(P<.04), referrals (P<.001), and in-hospital care provided by the pri
mary care physician (P<.001, chi(2)) than children in Boston and New H
aven. Patterns of primary care involvement also varied by source of ca
re within cities, after controlling for income and severity of illness
. Compared with children from Rochester community-based private practi
ces, children in Boston receiving care from health centers, hospitals,
or community-based private practices generally had 25% to 50% lower l
ikelihood of positive findings on all primary care involvement measure
s. Children in New Haven receiving care from community-based private o
r hospital-based practices also had lower rates, but involvement rates
were not higher when they received care from health centers. Other ch
ildren in Rochester and children receiving care from health maintenanc
e organizations in all cities demonstrated almost no significant diffe
rences compared with data from Rochester community practices. Conclusi
on: The source of primary care is associated with patterns of prehospi
tal and hospital care among hospitalized children, although specific a
ssociations vary by city.