Kotagal UR, Atherton HD, Eshett R, Schoettker PJ, Perlstein PH. Safety of Early Discharge for Medicaid Newborns. JAMA. 1999;282(12):1150-1156. doi:10.1001/jama.282.12.1150
Author Affiliations: Department of Pediatrics, Division of Health Policy & Clinical Effectiveness (Drs Kotagal and Perlstein, Mr Atherton, and Ms Schoettker) and the Division of Neonatology (Drs Kotagal and Perlstein), Children's Hospital Medical Center, and the Institute of Health Policy and Health Services Research (Dr Kotagal), University of Cincinnati, Cincinnati, Ohio; and the Bureau of Medicaid Policy, Ohio Department of Human Services, Columbus (Ms Eshett).
Context Neonates are being discharged from the hospital more rapidly, but the
risks associated with this practice, especially for low-income populations,
Objective To determine the impact of decreasing postnatal length of stay on rehospitalization
rates in the immediate postdischarge period for Medicaid neonates.
Design and Setting Retrospective, population-based cohort study using Ohio Medicaid claims
data linked to vital statistics files from July 1, 1991, to June 15, 1995.
Participants A total of 102,678 full-term neonates born to mothers receiving Medicaid
for at least 30 days after birth.
Main Outcome Measures Rehospitalization rates within 7 and 14 days of discharge, postdischarge
health care use, and regional variations in length of stay and rehospitalization.
Results The proportion of neonates who were discharged following a short stay
(less than 1 day after vaginal delivery, less than 2 days after cesarean birth)
increased 185%, from 21% to 59.8% (P<.001) and
the mean (SD) length of stay decreased 27%, from 2.2 (1.0) to 1.6 (0.9) days
(P<.001), over the course of the study. The proportion
of neonates who received a primary care visit within 14 days of birth increased
117% (P=.001). Rehospitalization rates within 7 and
14 days of discharge decreased by 23%, from 1.3% to 1.0% (P=.01), and by 19%, from 2.1% to 1.7% (P=.03),
respectively. Short stay across the 6 regions of the state varied significantly
over time (P<.001). Factors significantly associated
with increased likelihood of rehospitalization within both 7 and 14 days of
discharge were white race, shorter gestation, primiparity, earlier year of
birth, lower 5-minute Apgar score, vaginal delivery, married mother, and region
of the state.
Conclusion Our data suggest that reductions in length of stay for full-term Medicaid
newborns in Ohio have not resulted in an increase in rehospitalization rates
in the immediate postnatal period.
Rising health care costs and other recent market forces have brought
significant pressures on hospitals to discharge healthy newborns and their
mothers earlier than in the past. This movement to earlier discharge occurred
rapidly and with limited assessment of its safety.1,2
As a result, there have been documented increases in malnutrition and hyperbilirubinemia
(including kernicterus) in breastfeeding infants, infants of primiparous women,
and, particularly, immature infants.3- 5
Because most studies on early discharge of newborns have focused on middle-class,
commercially insured populations,6 the impact
of early discharge on the high-risk indigent and Medicaid-eligible populations,
for whom linkages to primary care may be less well established,7- 9
Some small studies have suggested that early discharge is likely to
be safe for Medicaid patients with strict criteria and careful follow-up,10- 13 but
concern remains about high rates of noncompliance with clinic visits in low-income
populations.10,14 Because neonatal
rehospitalization rates are low,1 few studies
have had the statistical power to detect clinically significant effects on
Changes in discharge policies for newborns due to market pressures since
1992 allowed us to use this natural experiment to evaluate the impact of changing
postnatal lengths of stay. The present study examines the effect of changes
in length of stay on immediate rehospitalization rates for newborns insured
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 1995. This combined database provided information on sociodemographic
characteristics of newborns and mothers, along with date of birth, date of
discharge, postdischarge health care use, diagnoses and procedures performed
during the birth hospitalization, and subsequent hospitalizations.
The source population for this study was all neonates born in Ohio from
July 1, 1991, to June 15, 1995 (Table 1). The last 2 weeks of June 1995 were eliminated due to incomplete
data. From this larger group, a subset of newborns and their mothers were
retained if they were Ohio Medicaid recipients, had a valid Medicaid birth
claim, and were enrolled in the Medicaid program for at least 30 days after
birth. Approximately 12% of the neonates were born to mothers enrolled in
Medicaid health maintenance organization plans and were excluded from the
analysis due to incomplete reporting. Healthy full-term newborns were identified
by 3 criteria: diagnosis related group 391 (normal newborn), birth weight
greater than 2000 g, and gestational age greater than 37 weeks. The birth
weight criterion of 2000 g was chosen to include all likely healthy newborns
cared for in the normal nursery even if of somewhat lower birth weight. The
study group was further divided by cesarean or vaginal birth.
The primary outcomes were rehospitalization rates within 7 and 14 days
of discharge. Demographic, maternal, prenatal, and neonatal characteristics
were examined. Prenatal care inadequacy was assessed using self-reported prenatal
visit information available from birth certificates.15
Because many women may visit a clinic or physician only for confirmation of
pregnancy, a conservative estimate of 2 or fewer visits was chosen to represent
minimal or absent prenatal care.
Length of stay was calculated as the difference between date of birth
and the date of the last claim for the hospital stay. A modified length-of-stay
variable, labeled "short stay," was defined as discharge within 1 day of vaginal
birth or within 2 days of cesarean birth. Postdischarge health care use was
measured by emergency department, primary care, and home health visits within
14 days of discharge.
Regional variations in length of stay, short stay, primary care visits,
and rehospitalization rates over time were determined for 6 previously described
perinatal service/education regions of the state.16
The primary diagnoses at rehospitalization and changes in rehospitalization
rates for the most common diagnoses over the study period were also examined.
We hypothesized that there would be a shift toward shorter length of
stay and that this would be associated with an increase in rehospitalization
rates. A preliminary study in 1 Ohio county revealed a rehospitalization rate
of 1.2% within 7 days and 2.4% within 14 days of discharge for healthy full-term
neonates. A sample of 39,000 patients was deemed necessary to detect a 20%
change in the rehospitalization rate within 7 days of discharge with an α
of .05 and 90% power. A sample of 19,000 was required to detect a 20% change
in rehospitalization within 14 days of discharge with 90% power at α=.05
Rehospitalization rates within 7 and 14 days of discharge were calculated.
The unit of analysis was the patient, so that only the first rehospitalization
within the specified period of time was measured. Mantel-Haenszel χ2 tests (analysis of trend for categorical variables) and t tests (continuous variables) were performed. Univariate analyses
were performed to compare patient and maternal characteristics of neonates
rehospitalized within 7 and 14 days of discharge with those not rehospitalized.
We then developed a multivariate logistic regression model for each primary
outcome of interest. The primary independent variable was whether the hospitalization
was a short stay. Potential confounders in the model included maternal age,
race, education, parity, prenatal care adequacy, year of birth, gestational
age, birth weight, route of delivery, 5-minute Apgar score, and region of
birth. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated
for the likelihood of being readmitted within 7 or 14 days of discharge.
To explore the possibility that the change over time in the rate of
short stays was different among the 6 regions of the state, 2 logistic models
of short stay were created. The first contained birth year and region of birth
(represented by binary dummy variables), and the second also included an interaction
variable for birth year and region. To determine if the 2 models were significantly
different, the log-likelihoods of the 2 models were computed and significance
determined from the χ2 distribution. Similar models were created
to determine if the 6 regions of the state differed in change in rehospitalization
rates over the study period. All statistical analyses were performed using
PC-SAS software (Release 6.12, SAS Institute Inc, Cary, NC).
There were 623,266 births recorded in Ohio between July 1, 1991, and
June 15, 1995. Of these, 194,748 neonates and their mothers were identified
as Medicaid recipients with valid claims. From that group, 102,678 healthy
full-term newborns (diagnosis related group 391, gestational age greater than
37 weeks, and birth weight greater than 2000 g) were still receiving Medicaid
30 days after birth, forming the final study cohort.
An examination of maternal characteristics (Table 1) showed a small, but statistically significant, increase
over time in the proportion of women who were white, primiparous, had 2 or
fewer prenatal visits, or completed high school and a decrease in the proportion
of married mothers. Gestational age, birth weight, and route of delivery remained
fairly stable over the period of study. There were no statistically significant
differences in these demographic variables between the 6 regions.
The mean (SD) hospital length of stay for newborns decreased in each
of the years examined, from 2.2 (1.0) days in 1991 to 1.6 (0.9) days in 1995,
a decrease of 27% (P<.001). In 1991, 20% of newborns
were discharged 1 day after birth and 76% after 2 days. By 1995, 54% were
discharged by 1 day and 88% by 2 days after birth. There was a concomitant
and statistically significant change in the percentage of newborns with short
stays (Table 1). The percentage
of newborns discharged after a short stay increased from 21.0% in 1991 to
59.8% in 1995, an increase of 185% (P<.001). The
increase in the short stay rate was statistically significant for both vaginal
and cesarean deliveries (P<.001).
There was considerable regional variation in length of stay for newborns
born between 1991 and 1995. Mean length of stay over the course of the study
was 1.9 days. It ranged from a low of 1.8 days in the southwest region of
the state to 2.1 days in the east central area. Mean length of stay decreased
in each year of the study in every region. The southwest region showed the
greatest change, a decrease of 43.5% (Table
2), while the east central region showed the least change, decreasing
The percentage of newborns discharged after a short stay (≤1 day
after vaginal delivery or ≤2 days after cesarean birth) varied widely between
regions and over the course of the study (Figure 1) but increased each year in every region (P<.001). The southwest region (Table 2) showed the greatest increase (553%). The northeast region
had the smallest percentage increase (117%). When modeled with the birth region–year
of birth interaction variable, the change in short stay over time was found
to differ significantly across the 6 regions for both vaginal and cesarean
The proportion of newborns who received a primary care visit within
14 days of discharge increased in each year of the study (Table 3), with an overall increase of 117% (P=.001). The proportion of newborns who received a home health visit
within 14 days of discharge, while still low, also increased significantly
(P=.001). There was a small, but statistically significant,
increase in the proportion of newborns who visited the emergency department
within 14 days of discharge (P=.001).
The increased proportion of neonates receiving a primary care visit
within 14 days of discharge was seen in each region (Figure 2). The proportion of newborns
receiving a home health visit within 14 days of discharge differed significantly
among the 6 regions (P=.001). The proportion having
a primary care or emergency department visit did not vary significantly.
In refutation of our hypothesis, there was a statistically significant
23% decrease in rehospitalization rates for healthy full-term newborns during
the course of the study (Table 4).
Rehospitalization rates within 7 days of discharge decreased from 1.3% in
1991 to 1.0% in 1995 (P=.01). The average rehospitalization
rate within 7 days of discharge during the study period was 1.1%. Similarly,
rehospitalization rates within 14 days of discharge decreased by 19%, from
2.1% in 1991 to 1.7% in 1995 (P=.03). The average
rate of rehospitalization within 14 days of discharge over the 4 years was
1.8%. In this population, 3.3% of the rehospitalized newborns were hospitalized
more than once within 14 days of the original discharge.
Five of the 6 regions showed decreasing rehospitalization rates within
7 days (Table 4), but these trends
were not statistically significant. These same 5 regions also had a decrease
in rehospitalization rates within 14 days of discharge. For 1 region, the
decrease was statistically significant (P=.04). The
6 regions did not significantly differ in their rate of decline in rehospitalization
Mothers of newborns readmitted within 7 days of discharge were significantly
more likely to be married, primiparous, and white (P<.001
for all). Rehospitalized newborns were more likely to have been delivered
vaginally (P<.001), have lower 5-minute Apgar
scores (8.98 vs. 9.05, P<.001), shorter mean gestations
(39.2 vs 39.5 weeks, P<.001) and shorter mean
length of stays (1.86 vs 1.94 days, P<.005). Maternal
age, maternal education, adequacy of prenatal care, birth weight, and short
stay rates were not statistically significant factors for rehospitalization
by 7 days after discharge.
Mothers of newborns readmitted within 14 days of discharge were significantly
more likely to be primiparous (P=.02), white (P=.01) and younger (mean age, 22.4 vs 22.8 y, P<.005). Rehospitalized newborns were more likely to have been delivered
vaginally (P<.002), have shorter gestations (39.3
vs 39.5 weeks, P<.001), lower birth weights (3345
vs 3367 g, P=.04), lower 5-minute Apgar scores (9.00
vs 9.04, P<.001) and shorter lengths of stay (1.89
vs 1.94 days, P=.04). Maternal marital status, education,
mean parity, prenatal care adequacy, and short stay rates were not significantly
associated with rehospitalization by 14 days after discharge.
After adjustment for other covariates, maternal factors significantly
associated with an increased risk of newborn rehospitalization within 7 days
of discharge (Table 5) included
primiparity (OR, 1.52 [95% CI, 1.26-1.83]), white race (OR, 1.34 [95% CI,
1.13-1.59]), and being married (OR, 1.30 [95% CI, 1.14-1.48]). Factors associated
with a decrease in the risk of rehospitalization included lower 5-minute Apgar
score (OR, 0.78 [95% CI, 0.71-0.87]), birth in the southeast region of the
state (OR, 0.76 [95% CI, 0.61-0.95]), cesarean birth (OR, 0.68 [95% CI, 0.56-0.82]),
and singleton birth (OR, 0.53 [95% CI, 0.32-0.88]). In addition, the odds
of rehospitalization decreased by 9% for each ensuing year of birth (OR, 0.91
[95% CI, 0.87-0.96]) and by 24% for each additional week of gestation (OR,
0.76 [95% CI, 0.72-0.80]). Maternal age, mean parity, adequacy of prenatal
care, maternal education, birth weight, short stay rate, and birth in other
regions of the state were not statistically significant predictors of 7-day
Similarly, adjusting for all factors, white race (OR, 1.21 [95% CI,
1.07-1.37]), primiparity (OR, 1.17 [95% CI, 1.02-1.34]), and being married
(OR, 1.14 [95% CI, 1.03-1.26]) were associated with a statistically significant
increase in the risk of rehospitalization within 14 days of discharge. The
odds of rehospitalization decreased 5% for each succeeding year of birth (OR,
0.95 [95% CI, 0.91-0.99]). Birth in the southeast region of the state (OR,
0.82 [95% CI, 0.69-0.97]), higher 5-minute Apgar score (OR, 0.82 [95% CI,
0.75-0.89]), and cesarean birth (OR, 0.82 [95% CI, 0.71-0.94]) were associated
with a significantly decreased risk of rehospitalization. Also, the odds of
rehospitalization decreased 1% for each 1-year increase in maternal age (OR,
0.99 [95% CI, 0.97-1.00]) and 16% for each additional week of gestation (OR,
0.84 [95% CI, 0.81-0.88]). Birth weight, singleton birth, parity, adequate
prenatal care, cesarean birth, short stay, maternal education, and birth in
other regions of the state were not statistically significant factors for
rehospitalization within 14 days of discharge.
When the results were stratified by race, birth in the southeast region
and age were no longer statistically significant factors for rehospitalization
within 14 days of discharge for white women. Primiparity, marriage, year of
birth, shorter gestation, cesarean birth, lower 5-minute Apgar score, along
with the new factors of singleton birth and birth in the east central region,
were statistically significant. For nonwhite mothers, only birth in the northeast
region was a statistically significant factor.
When the results were stratified by age, for mothers younger than 20
years, longer gestation, later year of birth, and higher 5-minute Apgar score
were associated with a statistically significant decrease in the risk of rehospitalization
within 14 days of discharge. For mothers older than 20 years, marriage, white
race, primiparity, lower 5-minute Apgar score, shorter gestation, birth in
the southeast region, and cesarean birth continued to be statistically significant
factors for rehospitalization within 14 days of discharge.
Most rehospitalizations were due to jaundice, which accounted for 42%
and 26% of hospitalizations within 7 days and 14 days of discharge, respectively
(Table 6). Readmission rates for
jaundice did not change significantly during the 4 years of the study. However,
readmission rates for jaundice within both 7 and 14 days of discharge did
differ significantly among the 6 regions of the state (P<.001).
The second most common reason for rehospitalization was respiratory
problems (8% and 10% of hospitalizations within 7 and 14 days of discharge,
respectively). Other diagnoses associated with rehospitalization included
fever, infections, disorders of the digestive system, bronchiolitis, dehydration,
and feeding problems. Only rehospitalizations for bronchiolitis increased
significantly over the course of the study (P=.009.)
Unlike previous reports, our analysis of full-term Medicaid births in
Ohio showed that a marked trend toward earlier discharge of newborns from
1991 to 1995 was not associated with greater rates of rehospitalization for
newborns during the same period. In fact, rehospitalizations for Medicaid
newborns decreased significantly during this time, both within 7 and 14 days
after discharge. While previous studies lacked the power to detect statistically
significant differences due to small numbers of rehospitalizations, our study
sample of 102,678 would have allowed us to detect a 13% change in readmission
rates (from 1.3% to 1.13%) with 90% power.
Our rehospitalization rates of 1.1% within 7 days and 1.8% within 14
days of discharge are similar to those reported elsewhere.5,10,17- 19
The lack of an increase in rehospitalizations seen in our study is similar
to results reported for Medicaid patients in other states.19,20
Using Maryland data from 1989 to 1992, Fox and Kanarek19
showed that the odds of readmission for healthy Medicaid newborns with shorter
lengths of stay were similar to those with longer lengths of stay. On the
other hand, in a large population-based study from Ontario,5
shorter lengths of stay were associated temporally with more rehospitalizations.
The Ontario study included all newborns and, because readmission data were
not linked to birth hospital data, adjustment for confounds that might affect
readmission rates was not done. In a case-control study of newborns in Washington
State,21 risk of readmission by 7, 14, and
28 days increased following early discharge. The groups at greatest risk were
those born to young or primiparous women and to mothers with premature rupture
of membranes. Thus, the risk factors for readmission identified in the Washington
study are similar to those seen in our study.
The primary reasons for rehospitalization in all of the aforementioned
studies were jaundice, breastfeeding failure, or dehydration. The risk for
clinically significant jaundice is known to be greater in breastfed newborns
compared with formula-fed newborns.3,10,17,20
Historically, breastfeeding rates are low in the Medicaid population.22,23 The overall breastfeeding rate in
the United States in the early postpartum period has been reported to be 54%,
while the rate for low-income mothers is only 32%.24
Although breastfeeding information was not available to us, the likely low
breastfeeding rate in our population may have played an important role in
the low rehospitalization rates that we observed.
Another significant reason for the lower rehospitalization rates may
have been better postdischarge coordination of care. Primary care visits and
home health care visits increased dramatically and there was a small, but
statistically significant, increase in visits to the emergency department.
This shift toward ambulatory care, along with low rates of breastfeeding,
may explain the reduced rates of rehospitalization we observed even in the
face of decreasing hospital lengths of stay.
Several studies have explored regional variations within a single state
for a single payer and patient population. Spong and Hulet25
found significant variation in length of stay and in the proportion of newborns
who have a short stay in different regions of the country. Our data show similar
variations and may reflect the influence of local market factors. For example,
in 1991, a powerful consortium of businesses in southwestern Ohio entered
into a collaborative partnership with area hospitals to lower the cost of
employee health care.26,27 Benchmarking
spurred competition among the hospitals, led to a dramatic reduction in health
care costs, and resulted in a coordinated newborn early discharge program.
Regional rates of readmissions may also reflect local variation in the patterns
and type of follow-up care. Although the demographic characteristics of the
population were similar among the 6 perinatal regions, the pattern of home
visits did vary significantly and may be an important factor.
Studies such as ours, using administrative data, are limited by the
lack of detail necessary to estimate length of stay in hours, to minimize
the likelihood of misclassification of short stay. To address this possible
problem, we examined length of stay for vaginal deliveries in a single hospital,
comparing short stay as it was defined in the present study with short stay
as determined by the number of hours between birth and discharge. This analysis
revealed that only 4.9% of those who should have been classified as short
stay were not. An additional 2.5% were classified as short stay, but should
not have been. Thus, we believe that misclassification errors were unlikely
to influence our findings.
In summary, in this population-based study of Medicaid newborns in Ohio,
significant decreases in postnatal length of stay were not associated with
an increase in rehospitalizations. It is important to state that reduced readmissions
do not necessarily imply better or comparable health of newborns, especially
when the same market forces influencing length of stay may discourage rehospitalization.
Rehospitalization may represent only 1 possible outcome of early discharge;
a shift to outpatient care, differences in breastfeeding rates, and changing
patterns of postdischarge care, such as home visits and use of home phototherapy,
may have played a role. Additional studies should be undertaken to determine
the reasons for these findings and to confirm them in other low-income populations.