J. Mauskopf et al., PATTERNS OF AMBULATORY CARE FOR AIDS PATIENTS, AND ASSOCIATION WITH EMERGENCY ROOM USE, Health services research, 29(4), 1994, pp. 489-510
Objective. We examined the association of patterns of ambulatory care
for AIDS patients with any use of the emergency room (ER) and the mont
hly rate of ER visits in the six months after AIDS diagnosis. Data Sou
rces/Study Setting. The study population was obtained from the New Yor
k State Medicaid HIV/AIDS Research Data Base and includes patients dia
gnosed with AIDS from 1983 to 1990. Data Collection/Extraction Methods
. To examine patterns of care and ER use not leading to hospitalizatio
n, we studied patients who survived at least six months after their fi
rst AIDS-defining diagnosis. The data noise included person level info
rmation on visits to different provider sites and patient demographic
and clinical characteristics. Study Design. We defined the dominant pr
ovider as the site delivering the majority of ambulatory care for pati
ents with a minimum of four ambulatory visits in the six months after
AIDS diagnosis. Dominant providers were classified by specialty and se
tting: generalist physician; general medicine clinic; AIDS specialty c
linic; and other specialty clinic or physician (e.g., cardiology). Pat
ients without a dominant provider were grouped into those with four or
more visits and those with fewer than four visits. Regression analysi
s was used to estimate relationships between ER use and patterns of am
bulatory care and patient demographic and severity of illness characte
ristics. Principal Results. The study population included 9,155 AIDS p
atients aged 13 to 60 years at diagnosis, continuously Medicaid-enroll
ed, and surviving at least six months after AIDS diagnosis. Among thos
e with four or more visits (56 percent), over 70 percent had a dominan
t provider. Overall, 39 percent of the study population visited the ER
while, in the group with four or more visits, 53 percent of those wit
hout a dominant provider had an ER visit. Patients without a dominant
provider were estimated to have 32 percent higher odds of ER use than
patients with a dominant provider. Among patients with a dominant prov
ider, patients with a generalist or primary care clinic dominant site
of care were estimated respectively to have 18 percent and 23 percent
lower odds than patients with an AIDS specialty clinic as the dominant
site of care. Drug users had higher odds of ER use, as did women. Con
clusions. In this Medicaid AIDS population, a dominant provider delive
ring the majority of a patient's care was associated with less use of
the ER by the patient. Among patients with a dominant provider, ER use
was lowest for those with a primary care provider. Further examinatio
n of the type and availability of ambulatory services in AIDS specialt
y clinics and primary care settings, as well as more detailed informat
ion on patient characteristics, may reveal reasons for these patterns
of ER use.