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Article
July 2002

Relationship Between Early Primary Care and Emergency Department Use in Early Infancy by the Medicaid Population

Author Affiliations

From the Center for Health Policy and Clinical Effectiveness (Dr Kotagal, Ms Schoettker, and Mr Atherton), the Divisions of Neonatology (Dr Kotagal) and Emergency Medicine (Drs Pomerantz and Schubert), Children's Hospital Medical Center, and the Institute of Health Policy and Health Services Research (Drs Kotagal and Hornung), University of Cincinnati, Cincinnati, Ohio; and the Bureau of Health Plan Policy, Ohio Department of Job and Family Services, Columbus (Ms Bush).

Arch Pediatr Adolesc Med. 2002;156(7):710-716. doi:10.1001/archpedi.156.7.710
Abstract

Objective  To examine the relationship between the use and type of primary care and visits to the emergency department (ED) in early infancy by healthy infants who are Medicaid recipients.

Design  A population-based cohort study using a database linking birth certificate data to Medicaid claims.

Participants  A total of 151 464 full-term infants born in Ohio to mothers receiving Medicaid from July 1, 1991, through June 30, 1998.

Main Outcome Measures  The primary outcome of interest was the occurrence of an ED visit within 91 days of the neonate's birth. Bivariate and multivariate analyses were performed to determine the effect of early linkage with primary care (within 21 days of birth) on ED use in early infancy.

Results  Only 53% of the infants had a documented primary care visit within 21 days of birth. Twenty-eight percent of infants had at least 1 ED visit within 91 days of birth and 9% had more than 1 visit. The mean age of the neonate at the first ED visit was 39.7 days. Fifteen percent of primary care visits within 21 days of birth occurred at a hospital-based primary care clinic. After adjusting for maternal, infant, and residency characteristics and temporal differences, early primary care linkage was associated with a 16% increase in the likelihood of ED use. When the primary care visit occurred in a hospital-based primary care clinic, it was associated with a 27% increase in the likelihood of ED use.

Conclusion  Contrary to our expectations, early primary care linkage did not result in a decreased risk of ED use.

PERSONS IN lower-income groups, especially poor families with young children, tend to use primary care at much lower rates than other groups.110 Failure to establish linkage with a primary care physician can have a negative influence on both the quality and cost of pediatric health care.11 Families without a primary care physician rely much more heavily on hospital emergency departments (EDs) for infant medical care and, therefore, tend to make more nonurgent visits to emergency facilities.12,13 The patterns of use of both primary care and emergency facilities can be established as early as the first year of life.12

Establishing a stable and consistent relationship with a primary care physician can provide families with continuity of care, advice, and support, and education on infant care.14 This concept, known as a medical home, attempts to address the complete needs of the patient.15,16 In contrast with primary care, ED visits usually focus on the presenting report, resulting in a lack of comprehensive assessment and preventive care, both of which are particularly important for young children.9,17

The use of the ED as a site of routine care has been noted in several studies and has been related to maternal perception of infant health and maternal and social variables as well as barriers to primary care use, such as lack of a medical home, transportation needs, and child care issues.1,2,1836 In previous studies at a single urban hospital in Ohio, we noted that up to 40% of all newborns discharged who were uninsured or receiving Medicaid used the ED for health care needs at least once in the first 3 months37,38 of life and 14% visited the ED before their first primary care visit.37

This study was undertaken to extend this research to a larger population. We examined the use, characteristics, and timing of the first primary care visit in relation to ED use by healthy infants in the Medicaid population throughout Ohio. We hypothesized that early linkage to primary care would be associated with decreased ED use.

PARTICIPANTS AND METHODS
STUDY DESIGN

We conducted a retrospective cohort study using Medicaid claims data linked to vital statistics files from the State of Ohio for fiscal years 1992 through 1998. This combined data set provided information on sociodemographic characteristics of infants and mothers, along with date of birth, date of discharge from the hospital, dates of primary care and ED visits, sites where health care was provided, and diagnoses and procedures performed during the birth hospitalization. This study was approved by the institutional review board; informed consent was not required.

POPULATION

The source population for this study was all births in Ohio from July 1, 1991 through June 30, 1998. From this larger group, a subset of infants and their mothers were selected who were Ohio Medicaid recipients, had a valid Medicaid birth claim, and were enrolled in the Medicaid program for at least 91 continuous days after the infant's birth. Infants born to mothers enrolled in Medicaid health maintenance organization plans (approximately 6% of the population) were excluded from the analysis owing to incomplete reporting. To isolate the relationship between primary care and ED use and to eliminate confusion related to predisposing illness, we restricted the study sample to healthy full-term neonates. Healthy full-term neonates in this group were identified by the following 3 criteria: diagnosis related group 391 (normal newborn), birth weight of 2000 g or more, and gestational age of 37 weeks or longer. These criteria have been used in other studies of postneonatal care.39

DATA VARIABLES

The primary outcome of interest was the occurrence of an ED visit within 91 days of birth. We chose to examine ED use within 91 days of birth because, in this data set, more than half of the infants who had any ED visit by 1 year of age had their first visit within 91 days of birth. Emergency department visits were identified by examining the Clinical Procedural Terminology (CPT) codes in the outpatient-physician claims. The CPT codes used to identify an ED visit were categorized as evaluation and management—ED services.40

The primary independent variable studied was the establishment of primary care linkage. Primary care linkage was defined as the occurrence of a visit to a primary care physician within 21 days of the neonate's birth. Primary care visits were selected by examining the CPT codes for each outpatient office visit. The visit was considered primary care if a CPT code in the categories of (1) office visit and evaluation, (2) preventive medicine, or (3) health check visit was present. The office visit and evaluation category consisted of CPT codes under the major heading of Evaluation and Management and the subheadings of Office or other outpatient services, Office or other outpatient consultation, and Confirmatory consultation.40 Preventive medicine and health check visits consisted of CPT codes under the major heading of Evaluation and Management and the subheading of Preventive medicine services.

Twenty-one days was chosen to allow for variation in the date of the first visit due to weekends and holidays. This was also verified by the peak of the first primary care visit that occurred around 15 days. The site of a primary care visit was classified as occurring at a community-based or hospital-based clinic location based on the "provider type" code in the Medicaid claim. If the provider type code was "general hospital," the visit was classified as hospital-based.

Confounders that might influence the relationship between primary care linkage and ED use were examined. These included maternal age, marital status, educational level, race, parity, and prenatal care visits. Newborn characteristics examined included year of birth, birth weight, gestational age, delivery route, and length of hospital stay. Jaundice was defined as the diagnosis of jaundice at discharge from the hospital, determined by International Classification of Diseases, Ninth Revision, Clinical Modification code. Year of birth was examined to address changes over time. To address rural vs urban influence, area of residence was stratified by whether the maternal county of residence was within a major metropolitan area of Ohio. Major metropolitan areas were obtained from US Bureau of the Census data.41 Regional variations in postdischarge health care and ED use over time were determined for the 6 perinatal service-education regions of the State of Ohio (ie, region 1, southwest; region 2, west central; region 3, northwest; region 4, southeast; region 5, northeast; and region 6, east central).42

DATA ANALYSIS

Bivariate analyses were performed to identify variables associated with hospital-based primary care visits and ED use in early infancy. χ2 Tests were used for analysis of categorical variables and t tests were performed for normally distributed continuous variables. Wilcoxon rank sum tests were used for nonnormally distributed data. Multivariate analysis for ED use within 91 days of birth was performed using a logistic regression model. Confounders were entered into the model if they were significant at a P = .05 level on bivariate analysis or if their inclusion changed the coefficient of the primary variable. Birth year was added to the model as a series of indicator variables for each year (1992-1998) with 1991 as the reference value. To examine possible interactions between maternal age and race and maternal age and marital status interaction terms for these variables were entered into the model. Regression diagnostics were used to assure a stable model. Odds ratios and associated 95% confidence limits (CLs) were calculated for the likelihood of visiting the ED within 91 days of birth. All statistical analyses were performed using SAS Statistical Software, Version 8.1 (SAS Institute Inc, Cary, NC).

RESULTS

There were 1 069 693 births recorded in Ohio between July 1, 1991, and June 30, 1998. Of these, 254 074 infants and their mothers were identified as Medicaid recipients 91 days after birth in fee-for-service plans. From that group, 151 464 healthy full-term infants (diagnosis related group, 391; gestational age, ≥37 weeks; and birth weight, ≥2000 g) formed the final study cohort. The general characteristics of the patient population are given in Table 1.

Table 1. 
General Characteristics of the Study Population*
General Characteristics of the Study Population*
PRIMARY CARE USE

Overall, only 53% of newborns made their first primary care visit within 21 days of birth and only 78% of infants in this population made at least 1 primary care visit within 3 months of the neonates' birth (Figure 1). Most early primary care visits (within 21 days) occurred at community clinics; only 15% occurred at a primary care clinic located within a hospital (Table 1). The proportion of newborns who received a primary care visit within 21 days of birth varied significantly between the 6 state perinatal regions, ranging from 43% to 58% (P<.001).

Distribution of the age of infants at their first primary care visit or emergency deparment (ED) visit within 91 days of birth.

Distribution of the age of infants at their first primary care visit or emergency deparment (ED) visit within 91 days of birth.

SITE OF PRIMARY CARE VISITS

Mothers who took their infants to hospital-based clinics for primary care clinics for more than 50% of their primary care visits were significantly more likely to be younger, primiparous, and to live in a major metropolitan area of Ohio. They were less likely to be white, married, or to have completed high school, and they were likely to have had significantly fewer prenatal care visits during their pregnancy. They had a significantly shorter mean length of stay at birth and were more likely to have had a home care visit within 21 days of birth.

ED USE

Of the 151 464 infants examined, over one quarter (Figure 1) had at least 1 ED visit within 3 months of the neonate's birth and 9% had more than 1 visit during this time. The mean age of the infants at the first ED visit was 39.7 days (Table 1). Infants who were taken to a hospital-based primary care clinic for most of their primary care visits were significantly more likely to use the ED. Emergeny department use between the 6 state perinatal regions varied from 25% to 31% (P<.001).

CHARACTERISTICS OF THOSE WHO USED THE ED

Infants who were taken to the ED within 91 days of birth were more likely to have had a primary care or home care visit within 21 days of birth and were more likely to have gone to hospital-based centers for most of their primary care visits (Table 2). Mothers of infants taken to the ED were significantly more likely to be younger and primiparous and less likely to be married or to have completed high school, but had significantly more prenatal care visits. They were significantly less likely to live in a major metropolitan county of Ohio. Race and a diagnosis of jaundice while in the birth hospital were not statistically different between the 2 groups.

Table 2. 
Bivariate Analysis of Patients With Any vs No Emergency Department Visits Within 91 Days of the Neonate's Birth*
Bivariate Analysis of Patients With Any vs No Emergency Department Visits Within 91 Days of the Neonate's Birth*

The proportion of infants who had at least 1 ED visit within 91 days of birth increased each year through 1995 and then began to decrease (Table 3), returning to near 1991 baseline values by 1998 (P<.001). In addition, significant regional variation was seen in ED use (P<.001).

Table 3. 
Bivariable Comparisons of Birth Year and Perinatal Region of Birth on Emergency Department (ED) Use Within 91 Days of the Neonate's Birth*
Bivariable Comparisons of Birth Year and Perinatal Region of Birth on Emergency Department (ED) Use Within 91 Days of the Neonate's Birth*
MULTIVARIATE ANALYSIS

Even after adjusting for maternal and infant risk variables, primary care use remained a significant factor affecting ED usage in this age group. Contrary to our expectations, however, having a primary care visit within 21 days of the neonate's birth not only did not decrease ED use but was actually associated with a 16% increase in the likelihood of ED use. When the primary care visit occurred at a hospital-based clinic, there was a similar, but even stronger, independent effect on ED, the likelihood of which increased by almost a third (Table 4).

Table 4. 
Adjusted Risk Factors for Emergency Department Use Within 91 Days of the Neonate's Birth
Adjusted Risk Factors for Emergency Department Use Within 91 Days of the Neonate's Birth

The maternal and infant factors most significantly associated with an increased risk of ED use within 91 days of the neonate's birth included less maternal education (no high school diploma), singleton birth, birth via cesarean section, and use of prenatal care. Compared with birth in 1991, birth in 1992 through 1996 was also significantly associated with an increased risk of ED use. Emergency department use decreased to baseline values in the later years. Factors associated with a decrease in the risk of ED use included primiparity, longer gestational age, and heavier birth weight. The interaction between increasing maternal age and nonwhite race and the interaction between increasing maternal age and single marital status were both associated with an increase in the odds of ED use. Residence in a nonmetropolitan area was associated with an increased risk of newborn ED use within 91 days of birth. Compared with perinatal region 1, residence in regions 2, 3, 4, and 6 were associated with increased ED use.

To address the possibility that the primary care and ED visits were part of the same care episode, the analysis was also run after excluding all patients with an ED visit prior to 30 days after the neonate's birth, allowing for a 9-day gap between the primary care and ED visit. The result was only a very small change in the adjusted odds ratio for a primary care visit (from 1.170 to 1.165).

COMMENT

We found that only half of the infants in this population had a documented early linkage to primary care. Almost one third of the infants had at least 1 ED visit in early infancy and almost 10% had more than 1 ED visit. Contrary to our expectations, infants who were taken to the ED within 91 days of birth were likely to have had more prenatal care visits and were more likely to have had early primary care linkage. They were more likely to have gone to hospital-based primary care clinics for most of their visits. Even after adjusting for maternal, infant, and residency characteristics, early primary care linkage did not result in a decreased risk of ED use in early infancy.

Several studies have shown that children insured through the Medicaid program use hospital EDs more frequently than privately insured children, particularly for nonurgent reasons.5,36,43 In a study similar to ours, Sharma et al44 followed almost 73 000 infants in Missouri from their birth in 1995 through their first birthday and documented similar trends. In their study, Medicaid coverage was the most important predictor of ED use. Other factors associated with ED use included self-pay, black race, rural residency, presence of birth defects, and a nursery stay of longer than 2 days. The Medicaid patients in their study, however, had similar rates of ED use in both urban and rural areas. For our population of Medicaid patients, residence in a nonmetropolitan area was associated with an increased risk of newborn ED use.

Emergency department use increased during the first few years of the study, appeared to peak in 1995, and then began to decrease, returning to baseline levels by 1997. These observations may be related to changes in the timing of discharge of newborns occurring at this time.39

Although many studies have examined the issue, there are no conclusive answers as to why parents routinely seek nonurgent ED care for their children. Reported possibilities include health care beliefs, convenience, socioeconomic issues, role modeling, overestimation of the severity of the illness, failure to understand how and when to access the health care system, and availability of a primary care physician.4,34,4549

Conventional wisdom states that improvements in primary care services will result in decreases in ED use.50 The benefits of improved access to primary care have been suggested in some previous studies. Several have shown a decrease in ED use after establishment of community health centers10,13,51 and others have shown that patients with a regular source of care are less likely to use the ED.22 Gill and Diamond52 reported a decrease in ED use simply as a result of referral to a primary care physician. However, many families with a regular source of care continue to exhibit an uncoordinated pattern of seeking care. Glotzer et al53 reported that prior approval requirements did not visibly change how patients used the ED and Gadomski et al43 found that ED visits were not significantly reduced after institution of a Maryland program that involved assignment to a primary care physician with gatekeeping responsibility.

We have previously shown that women with poor prenatal care are less likely to seek ED care for their young infants.54 In the current study, mothers who took their infants to the ED also used other sources of health care. They seemed to split their children's health care between a primary care site and the ED or to use the ED as a backup to their usual source of care. Habenstreit55 speculated that some patients who have a regular source of care may prefer to use the ED for unexpected illnesses and, since EDs are open all hours, they may serve as the designated acute-care facility when the clinic or physician office is closed.56 Even a nonurgent ED visit may be appropriate at a time when no other alternate health care is available.

All studies using administrative data, such as ours, are limited by the accuracy and completeness of the unaudited claims data.57,58 In addition, studies using large data sets, such as ours, often detect differences that are statistically significant but not clinically relevant. Despite this caution, large differences were observed for 5 important characteristics that appear to be significant for ED use in early infancy. These include an early primary care visit, primary care at a hospital-based clinic, maternal education, maternal age, and birth year.

Unfortunately, our data set did not provide information on the time or urgency of the ED visits. We also do not know how many mothers contacted their physician before going to the ED. A recent study of full-term neonates discharged from a single newborn nursery in Ohio found that one third of all ED visits were made when the primary care physicians' offices were open and 58% of these ED visits were determined to be nonurgent.59 Only 15% of all visits to the ED were referred by a primary care physician. Twenty-nine percent of physician-referred visits were determined to be nonurgent while 64% of the self-referred visits were nonurgent. Our results are further limited by being restricted to fee-for-service Medicaid patients from a single state, although a recent study of Medicaid infants in an urban tertiary care center found no difference in ED usage patterns between managed care and fee-for-service enrollees.60

In this high-risk population, having a primary care visit within 21 days of the neonate's birth and having the primary care visit at a hospital-based clinic were not associated with a decreased risk of ED use within 91 days of birth. In fact ED use increased in this population even after adjusting for possible confounders. This implies that simply having a primary care visit does not influence ED use. Alternatively, mothers seeking care may not perceive the ED and the primary care clinic as representing different health care systems, but rather make their choice based on convenience. The results of this study suggest that the focus should shift to measuring and improving the quality of the primary care services, especially around access, but based on the perceptions of the users of the services themselves. The quality and effectiveness of primary care services also needs to be monitored carefully by payers of care to ensure that they meet the needs of users. Alternatively, the ED could be seen as a reasonable, significant and integral part of the system of providing care for the Medicaid population. Models focusing on delivering primary care in this setting should be tested.

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Article Information

Accepted for publication March 19, 2002.

This study was supported in part by a Medical Technical Assistance and Policy Program grant from the Ohio Department of Human Services Bureau of Medicaid Policy, Columbus (Dr Kotagal).

What This Study Adds

The use of the ED as a site of routine care has been noted in several studies and has been related to maternal perception of infant health and maternal and social variables as well as barriers to primary care use, such as lack of a medical home, transportation needs, and child care issues. In previous studies at a single urban hospital in Ohio, we noted that up to 40% of all newborns discharged who were uninsured or receiving Medicaid used the ED for health care needs at least once in the first 3 months and 14% visited the ED before their first primary care visit.

The present study was undertaken to extend this research to a larger population. We hypothesized that early linkage to primary care would be associated with decreased ED use. However, contrary to our expectations, infants in this population who were taken to the ED within 91 days of birth were likely to have had more prenatal care visits and were more likely to have had early primary care linkage. They were more likely to have gone to hospital-based primary care clinics for the majority of their visits. Even after adjusting for maternal, infant, and residency characteristics, early primary care linkage did not result in a decreased risk of ED use in early infancy.

Corresponding author and reprints: Uma R. Kotagal, MBBS, MSc, Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039 (e-mail: Uma.Kotagal@chmcc.org).

References
1.
MacKoul  DFeldman  MSavageau  JKrumholz  A Emergency department utilization in a large pediatric group practice. Am J Med Qual. 1995;1088- 92Article
2.
Baker  DWStevens  CDBrook  RH Regular source of ambulatory care and medical care utilization by patients presenting to a public hospital emergency department. JAMA. 1994;2711902- 1912Article
3.
Buesching  DPJablonowski  AVesta  E  et al.  Inappropriate emergency department visits. Ann Emerg Med. 1985;14672- 676Article
4.
Grumbach  KKeane  DBindman  A Primary care and public emergency department overcrowding. Am J Public Health. 1993;83372- 378Article
5.
Medicaid Access Study Group, Access of Medicaid recipients to outpatient care. N Engl J Med. 1994;3301426- 1430Article
6.
Padgett  DKBrodsky  B Psychosocial factors influencing non-urgent use of the emergency room: a review of the literature and recommendations for research and improved service delivery. Soc Sci Med. 1992;351189- 1197Article
7.
Young  GPWagner  MBKellerman  ALEllis  JBouley  Dfor the 24 Hours in the ED Study Group, Ambulatory visits to hospital emergency department: patterns and reasons for use. JAMA. 1996;276460- 465Article
8.
Smith  RDMcNamara  JJ Why not your pediatrician's office? a study of weekday pediatric emergency department use for minor illness care in the community hospital. Pediatr Emerg Care. 1988;4107- 111Article
9.
Kasper  JD The importance of type of usual source of care for children's physician access and expenditures. Med Care. 1987;25386- 398Article
10.
Ullman  RBlock  JAStratmann  WC An emergency room's patients: their characteristics and utilization of hospital services. Med Care. 1975;131011- 1020Article
11.
Alpert  JJRobertson  LSKosa  JHeagarty  MCHaggerty  RJ Delivery of health care for children: report of an experiment. Pediatrics. 1976;57917- 930
12.
Fosarelli  PDeAngelis  CMellits  ED Health services use by children enrolled in a hospital-based primary care clinic: a longitudinal perspective. Pediatrics. 1987;79196- 202
13.
Hochheiser  LIWoodward  KCharney  E Effect of the neighborhood health center on the use of pediatric emergency departments in Rochester, New York. N Engl J Med. 1971;285148- 152Article
14.
de Alteriis  MFanning  T A public health model of Medicaid emergency room use. Health Care Financ Rev. 1991;1215- 20
15.
Hughes  JRGrayson  RStiles  FC Fragmentation of care and the medical home. Pediatrics. 1977;60559
16.
Sia  CC Abraham Jacobi Award Address, April 14, 1992: the medical home: pediatric practice and child advocacy in the 1990s. Pediatrics. 1992;90419- 423
17.
Mitchell  CKFranco  SM Factors associated with improved immunization rates for urban minority pre-school children. Clin Pediatr (Phila). 1995;34466- 470Article
18.
Norr  KFNacion  KWAbramson  R Early discharge with home follow-up: impacts on low income mothers and infants. J Obstet Gynecol Neonatal Nurs. 1989;18133- 141Article
19.
Gill  JM Nonurgent use of the emergency department: appropriate or not? Ann Emerg Med. 1994;24953- 957Article
20.
Spivak  HRLevy  JCBonanno  RACracknell  M Patient and provider factors associated with selected measures of quality of care. Pediatrics. 1980;65307- 313
21.
Feigelman  SDuggan  AKBazell  CMBaumgardner  RAMellits  EDDeAngelis  C Correlates of emergency room utilization in the first year of life. Clin Pediatr (Phila). 1990;29698- 705Article
22.
Orr  STCharney  EStraus  JBloom  B Emergency room use by low-income children with regular source of health care. Med Care. 1991;29283- 296Article
23.
Oberlander  TFPless  IBDougherty  GE Advice seeking and appropriate sue of a pediatric emergency department. AJDC. 1993;147863- 867
24.
Mayefsky  JHEl-Shinaway  YKelleher  P Families who seek care for the common cold in a pediatric emergency department. J Pediatr. 1991;119933- 934Article
25.
Wood  DLHayward  RACorey  CRFreeman  HEShapiro  MF Access to medical care for children and adolescents in the United States. Pediatrics. 1990;86666- 673
26.
Hansagi  HCarlsson  BBrismar  B The urgency of care need and patient satisfaction at a hospital emergency department. Health Care Manage Rev. 1992;1771- 75Article
27.
Hilditch  JR Changes in hospital emergency department use associated with increased family physician availability. J Fam Pract. 1980;1191- 96
28.
Kelman  HRLane  DS Use of the hospital emergency room in relation to use of private physicians. Am J Public Health. 1976;66891- 894Article
29.
Shesser  RKirsch  TSmith  JHirsch  R An analysis of emergency department use by patients with minor illness. Ann Emerg Med. 1991;20743- 748Article
30.
Vaughan Jr  HFGamester  CE Why patients use hospital emergency departments. Hospitals. 1966;4059- 62passim
31.
Pisarcik  G Why patients use the emergency department. J Emerg Nurs. 1980;616- 21
32.
Wabschall  JM Why parents use the emergency department for nonemergency infant care. J Emerg Nurs. 1983;937- 40
33.
Liu  TSayre  MRCarleton  SC Emergency medical care: types, trends, and factors related to nonurgent visits. Acad Emerg Med. 1999;61147- 1152Article
34.
Chande  VTKrug  SEWarm  EF Pediatric emergency department utilization habits: a consumer survey. Pediatr Emerg Care. 1996;1227- 30Article
35.
Jones  DSMcNagny  SEWilliams  MVParker  RMSawyer  MFRask  KJ Lack of a regular source of care among children using a public hospital emergency department. Pediatr Emerg Care. 1999;1513- 16Article
36.
St Peter  RFNewacheck  PWHalfon  N Access to care for poor children: separate and unequal? JAMA. 1992;2672760- 2764Article
37.
Cooper  WOKotagal  URAtherton  HD  et al.  Use of health care services by inner-city infants in an early discharge program. Pediatrics. 1996;98 ((4 Pt 1)) 686- 691
38.
Kotagal  URAtherton  HDBragg  ELippert  CDonovan  EFPerlstein  PH Use of hospital-based services in the first three months of life: impact of an early discharge program. J Pediatr. 1997;130250- 256Article
39.
Kotagal  URAtherton  HDEschett  RSchoettker  PJPerlstein  PH Safety of early discharge for Medicaid newborns. JAMA. 1999;2821150- 1156Article
40.
Not Available, Current Procedural Terminology, CPT 2000.  Chicago, Ill American Medical Association1999;
41.
US Bureau of the Census, Metropolitan area rankings. Available athttp://www.census.gov/Press-Release/metro01.prnAccessed August 20, 2000
42.
Not Available, State Perinatal Guidelines.  Ohio Dept of Health, Division of Maternal and Child Healthadopted October 1997
43.
Gadomski  AMPerkis  VHorton  L Diverting managed care Medicaid patients from pediatric emergency department use. Pediatrics. 1995;95170- 178
44.
Sharma  VSimon  SDBakewell  JMEllerbeck  EFFox  MHWallace  DD Factors influencing infant visits to emergency departments. Pediatrics. 2000;1061031- 1039Article
45.
Hoffman  CBroyles  RSTyson  JE Emergency room visits despite the availability of primary care: a study of high risk inner city infants. Am J Med Sci. 1997;31399- 103Article
46.
Kini  NMStrait  RT Nonurgent use of the pediatric emergency department during the day. Pediatr Emerg Care. 1998;1419- 21Article
47.
Phelps  KTaylor  CKimmel  SNagel  RKlein  WPuczynski  S Factors associated with emergency department utilization for nonurgent pediatric problems. Arch Fam Med. 2000;91086- 1092Article
48.
Halfon  NNewacheck  PWWood  DLSt Peter  RF Routine emergency department use for sick care by children in the United States. Pediatrics. 1996;9828- 34
49.
Ellen  JMOtt  MASchwarz  DF The relationship between grandmothers' involvement in childcare and emergency department utilization. Pediatr Emerg Care. 1995;11223- 225Article
50.
Piehl  MDClemens  CJJoines  JD "Narrowing the Gap": decreasing emergency department use by children enrolled in the Medicaid program by improving access to primary care. Arch Pediatr Adolesc Med. 2000;154791- 795Article
51.
Moore  GTBernstein  RBonanno  RA Effect of a neighborhood health center on hospital emergency room use. Med Care. 1972;10240- 247Article
52.
Gill  JMDiamond  JJ Effect of primary care referral on emergency department use: evaluation of a statewide Medicaid program. Fam Med. 1996;28178- 182
53.
Glotzer  DSager  ASocolar  DWeitzman  M Prior approval in the pediatric emergency room. Pediatrics. 1991;88674- 680
54.
Donovan  EFPerlstein  PHAtherton  HDKotagal  UR Prenatal care and infant emergency department use. Pediatr Emerg Care. 2000;16156- 159Article
55.
Habenstreit  B Health care patterns of non-urgent patients in an inner city emergency room. N Y State J Med. 1986;86517- 521
56.
DeAngelis  CFosarelli  PDuggan  AK Use of emergency department by children enrolled in a primary care clinic. Pediatr Emerg Care. 1985;161- 65Article
57.
Walkup  JTBoyer  CAKellermann  SL Reliability of Medicaid claims files for use in psychiatric diagnoses and service delivery. Adm Policy Ment Health. 2000;27129- 139Article
58.
Steinwachs  DMStuart  MEScholle  SStarfield  BFox  MHWeiner  JP A comparison of ambulatory Medicaid claims to medical records: a reliability assessment. Am J Med Qual. 1998;133- 69Article
59.
Pomerantz  WJSchubert  CJAtherton  HDKotagal  UR Characteristics of non-urgent emergency department in the first three months of life. Pediatr Emerg Care. In press
60.
Alessandrini  EAShaw  KNBilker  WBPerry  KABaker  MDSchwarz  DF Effects of Medicaid managed care on health care use: infant emergency department and ambulatory services. Pediatrics. 2001;108103- 110Article
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