Keywords
cesarean section/economics - cesarean section/utilization - pregnancy - cesarean delivery
- length of stay - readmission - facility variation
The duration of hospitalization following many types of surgery continues to decline
in the United States.[1] Obstetrics and gynecology is no exception to this trend; total laparoscopic hysterectomy
is now commonly a same-day, outpatient procedure.[2] However, studies of length of stay following childbirth in the United States have
been colored by concern regarding inappropriately early obstetric discharge. Between
the 1970s and middle 1990s, there was a dramatic reduction in length of stays following
both vaginal and cesarean deliveries.[3] This trend captured considerable popular attention due to concerns that patients
were discharged from the hospital prematurely, with these trends described as creating
“drive through deliveries.”[4] Based on these concerns, states passed legislation mandating entitlement to a fixed
number of hospital days following vaginal and cesarean deliveries. This culminated
with federal legislation via passage of the Newborns' and Mothers' Health Protection
Act (NMHPA) of 1996, which created an entitlement to a 96-hour hospitalization after
cesarean delivery for patients covered by many types of private insurance plans. While
mothers are entitled to this duration of hospitalization, patients may be discharged
earlier based on assessment of their attending physician.
Since passage of the NMHPA more than 20 years ago, there has been continued improvements
in the evidence-based informing performance of cesarean delivery and anesthetic practice.[5] Furthermore, American health care is known to have substantial variation in practice
patterns based on the type of facilities in which patients receive treatment.[6] Whether this variation and its potential impact on outcome exists in postcesarean
discharge duration is unknown. Thus, the objectives of this study were to (1) characterize
contemporary duration of stay following cesarean delivery in the United States, (2)
ascertain whether facility variation exists in duration of stay, and (3) determine
whether shorter durations of stay (of 2 days or fewer) are associated with differences
in rates of hospital maternal readmission or costs.
Materials and Methods
We used data from the 2017 Nationwide Readmissions Database (NRD), Healthcare Cost
and Utilization Project, Agency for Healthcare Research and Quality.[7] The 2017 NRD is an all-payor administrative dataset containing most acute care,
short stay hospitalizations for 28 states, comprising 60.0% of the U.S. population
and 58.2% of all hospitalizations. The data in each record includes demographic information
about the patient, including age, gender, diagnosis and procedure codes, information
about the treating hospital including location and academic affiliation, and outcome
information including length of stay, inpatient charges, and discharge disposition.
Record linkage allows identification of subsequent hospitalizations across the year
for the same patient (within the same state). Cost-to-charge ratio files are provided
with the data to enable conversion from hospital charges to estimated hospital cost.
Patients who underwent a low transverse cesarean delivery were included based on the
use of International Classifications of Diseases, 10th Edition, Clinical Modification
(ICD-10-CM) procedure code 10D00Z1. The NRD includes variables indicating the number
of days from date of admission to the date each procedure was performed, and as well
as total length of stay. The difference between these two variables was used to calculate
the postcesarean length of stay (i.e., the length of stay presented here is the time
subsequent to cesarean delivery). Only patients whose discharge destination was to
home (with or without home care) were included. This study was intended to focus on
low-risk patients. We identified both the presence of significant maternal morbidity
during the patients' delivery hospitalization, as well as comorbid conditions, using
a previously validated algorithm, which we updated to ICD-10-CM diagnostic codes.[8] All patients who had evidence of significant maternal morbidity were excluded, as
were patients who had a comorbid condition that, in our clinical opinion, might necessitate
longer inpatient postoperative care (specifically, pulmonary hypertension, sickle
cell disease, preeclampsia, chronic kidney disease, ischemic heart disease, congenital
or valvular cardiac disease, cystic fibrosis, or morbidly adherent placenta). To further
limit the cohort to patients who might be considered reasonable for early discharge,
patients whose delivery was complicated by preterm birth, fetal demise, maternal cardiovascular
disease, uterine rupture, and delayed twin birth were removed as identified in published
quality indicators for primary cesarean delivery updated to ICD-10-CM criteria by
us,[9] and we additionally excluded chorioamnionitis (O41.1x). Due to the need for a 30-day
follow-up period to calculate readmission rates, patients discharged in December 2017
were excluded. Patients who had multiple delivery records in the same year or for
whom the date of the cesarean delivery procedure was unavailable were omitted, since
it would not be possible to calculate the postdelivery length of stay without this
information. As facility variation was a key focus of the analysis, observations from
facilities in which fewer than 10 patients met study criteria were excluded.
The data were summarized using mean and median for continuous data and percentages
for categorical data. Comorbid conditions and indications for cesarean delivery were
identified using previously described criteria from the discharge diagnosis codes,
updated to ICD-10-CM.[8]
[10] Weights were incorporated to reflect the sampling strategy underlying the NRD. To
assess for predictors of shorter hospitalizations (defined as a postcesarean length
of stay of 2 days or less), a hierarchical logistic regression was then used to model
hospital length of stay less than or equal to 2 days as a function of patient and
hospital characteristics, incorporating variation at the hospital level using random
effects. The variation in lengths of stay following cesarean delivery at the facility
level were then calculated, based on both percentage of patients discharged within
2 days of delivery and by mean length of stay. To assess whether variations in facility-level
length of stay following cesarean delivery were associated with differences in an
individual's probability of readmission and inpatient costs, regression models (logistic
for readmission and gamma log link for costs) were constructed, predicting outcome
as a function of the patient's individual characteristics, hospital characteristics,
and the facility rate of discharge within 2 days of delivery, with standard errors
clustered by facility. To improve interpretability, the results were transformed from
their native odds ratio scale for logistic regression to relative risks and absolute
risk differences, and from the native multiplicative effect for the gamma log link
regression to an incremental effect. As each individual's length of stay is likely
confounded with their outcome, when calculating the facility length of stay metrics,
the metric was recalculated for each individual to exclude that individual's length
of stay. Alternative formulations of these models, including specifying the facility
rate using quadratic, categorical (quartiles), and a restricted cubic spline using
three quartile-based knots were performed to assess robustness to the choice of model
specification, and an alternative measure of facility length of stay (mean length
of stay) was also modeled to assess robustness to choice of measure for the readmission
outcome.
A two-sided α value of 0.05 was specified as statistically significant. Missing data
elements were minimal (<1% for all variables) and were addressed with imputing based
on modal value. The data were analyzed in Stata Statistical Software, Version 16.1
(Statacorp, College Station, TX). Given this study is a retrospective analysis using
an existing limited dataset, the Johns Hopkins University School of Medicine Institutional
Review Board determined it to be exempted from review.
Results
A total of 456,312 patients who delivered at 1,535 facilities met inclusion criteria
([Fig. 1]). When weighted to produce estimates of the national population, rather than only
the sample included in the NRD dataset, this sample equates to 848,556 patients. Of
these patients, the median length of stay was 3 days, and the mean length of stay
was 2.7 days. Very few (1.8%) patients stayed less than 2 days following cesarean
delivery, or more than 4 days (1.2%); most patients stayed 2 days (39.1%), 3 days
(46.4%), or 4 days (11.5%). Mean age in the cohort was 29.9 years, the majority (54.0%)
was insured by private insurance, and most (52%) had a history of prior cesarean delivery
([Table 1]). The overall maternal readmission rate was 1.7%, and total inpatient costs were
estimated at $6,800 per admission.
Fig. 1 Derivation of study sample.
Table 1
Baseline patient and facility characteristics, stratified by length of stay
|
Length of stay following cesarean delivery (d)
|
|
Overall
(N = 456,312) (weighted N = 848,556)
|
<2 d
(N = 8,276)
(weighted N = 15,533)
|
2 d
(N = 178,474)
(weighted N = 332,781)
|
3 d
(N = 211,605)
(weighted N = 394,795)
|
4 d
(N = 52,693)
(weighted N = 96,012)
|
>4 d
(N = 5,264)
(weighted N = 9,435)
|
p-Value
|
|
Mean (standard deviation) or %
|
|
Age in y at admission
|
29.9 (5.7)
|
29.2 (5.5)
|
29.3 (5.5)
|
30.0 (5.8)
|
31.1 (5.9)
|
30.5 (6.3)
|
<0.001
|
|
Primary payer
|
|
Medicare
|
7,953 (0.9)
|
93 (0.6)
|
2,551 (0.8)
|
3,731 (0.9)
|
1,331 (1.4)
|
247 (2.6)
|
<0.001
|
|
Medicaid
|
349,491 (41.2)
|
6,731 (43.3)
|
142,285 (42.8)
|
162,534 (41.2)
|
33,849 (35.3)
|
4,093 (43.4)
|
|
Private
|
457,887 (54.0)
|
7,693 (49.5)
|
173,122 (52.0)
|
214,465 (54.3)
|
57,845 (60.2)
|
4,763 (50.5)
|
|
Self-pay
|
10,281 (1.2)
|
454 (2.9)
|
4,400 (1.3)
|
4,443 (1.1)
|
855 (0.9)
|
129 (1.4)
|
|
No charge
|
416 (0.0)
|
18 (0.1)
|
137 (0.0)
|
217 (0.1)
|
33 (0.0)
|
(0.1)[a]
|
|
Other
|
22,529 (2.7)
|
544 (3.5)
|
10,286 (3.1)
|
9,405 (2.4)
|
2,099 (2.2)
|
195 (2.1)
|
|
Control/ownership of hospital
|
|
Government, nonfederal
|
92,418 (10.9)
|
2,237 (14.4)
|
45,320 (13.6)
|
37,570 (9.5)
|
6,538 (6.8)
|
753 (8.0)
|
<0.001
|
|
Private, nonprofit
|
645,943 (76.1)
|
10,437 (67.2)
|
235,140 (70.7)
|
312,587 (79.2)
|
80,227 (83.6)
|
7,552 (80.0)
|
|
Private, investor-owned
|
110,195 (13.0)
|
2,859 (18.4)
|
52,321 (15.7)
|
44,638 (11.3)
|
9,247 (9.6)
|
1,130 (12.0)
|
|
Teaching status of urban hospitals
|
|
Metropolitan nonteaching
|
186,918 (22.0)
|
4,040 (26.0)
|
85,984 (25.8)
|
77,385 (19.6)
|
17,814 (18.6)
|
1,694 (18.0)
|
<0.001
|
|
Metropolitan teaching
|
578,867 (68.2)
|
7,994 (51.5)
|
197,715 (59.4)
|
290,987 (73.7)
|
74,847 (78.0)
|
7,324 (77.6)
|
|
Nonmetropolitan hospital
|
82,771 (9.8)
|
3,499 (22.5)
|
49,081 (14.7)
|
26,423 (6.7)
|
3,351 (3.5)
|
417 (4.4)
|
|
Bed size of hospital
|
|
Small
|
137,589 (16.2)
|
2,976 (19.2)
|
57,953 (17.4)
|
62,125 (15.7)
|
13,335 (13.9)
|
1,200 (12.7)
|
0.02
|
|
Medium
|
251,640 (29.7)
|
4,653 (30.0)
|
100,057 (30.1)
|
119,851 (30.4)
|
24,687 (25.7)
|
2,392 (25.4)
|
|
Large
|
459,327 (54.1)
|
7,904 (50.9)
|
174,772 (52.5)
|
212,819 (53.9)
|
57,990 (60.4)
|
5,843 (61.9)
|
|
Zip code median household income ($1,000s)
|
|
1–43.9
|
235,253 (27.7)
|
5,191 (33.4)
|
108,155 (32.5)
|
101,094 (25.6)
|
18,413 (19.2)
|
2,400 (25.4)
|
<0.001
|
|
44.0–55.9
|
232,559 (27.4)
|
4,979 (32.1)
|
100,272 (30.1)
|
103,549 (26.2)
|
21,291 (22.2)
|
2,467 (26.1)
|
|
56.0–73.9
|
205,889 (24.3)
|
3,420 (22.0)
|
75,369 (22.6)
|
100,366 (25.4)
|
24,556 (25.6)
|
2,178 (23.1)
|
|
74.0+
|
174,855 (20.6)
|
1,943 (12.5)
|
48,984 (14.7)
|
89,786 (22.7)
|
31,751 (33.1)
|
2,390 (25.3)
|
|
Number of patients at facility in cohort
|
717.1 (775.3)
|
472.6 (513.8)
|
587.6 (578.9)
|
780.8 (819.1)
|
898.2 (1,011.7)
|
1,178.9 (1,438.0)
|
<0.001
|
|
Comorbid conditions
|
|
Placenta previa
|
9,038 (1.1)
|
140 (0.9)
|
2,509 (0.8)
|
4,468 (1.1)
|
1,768 (1.8)
|
152 (1.6)
|
<0.001
|
|
Gestational hypertension
|
58,809 (6.9)
|
852 (5.5)
|
19,094 (5.7)
|
28,399 (7.2)
|
8,688 (9.0)
|
1,777 (18.8)
|
<0.001
|
|
Preexisting hypertension
|
28,547 (3.4)
|
454 (2.9)
|
10,157 (3.1)
|
13,216 (3.3)
|
3,919 (4.1)
|
803 (8.5)
|
<0.001
|
|
Systemic lupus erythematosus
|
1,226 (0.1)
|
18 (0.1)
|
384 (0.1)
|
608 (0.2)
|
191 (0.2)
|
25 (0.3)
|
<0.001
|
|
Human immunodeficiency virus
|
1,300 (0.2)
|
15 (0.1)
|
355 (0.1)
|
754 (0.2)
|
161 (0.2)
|
16 (0.2)
|
<0.001
|
|
Drug abuse
|
21,348 (2.5)
|
563 (3.6)
|
7,417 (2.2)
|
9,280 (2.4)
|
3,554 (3.7)
|
535 (5.7)
|
<0.001
|
|
Alcohol abuse
|
1,038 (0.1)
|
30 (0.2)
|
349 (0.1)
|
477 (0.1)
|
146 (0.2)
|
35 (0.4)
|
<0.001
|
|
Tobacco use
|
50,069 (5.9)
|
1,491 (9.6)
|
23,642 (7.1)
|
19,461 (4.9)
|
4,817 (5.0)
|
658 (7.0)
|
<0.001
|
|
Asthma
|
45,630 (5.4)
|
658 (4.2)
|
15,339 (4.6)
|
22,335 (5.7)
|
6,543 (6.8)
|
754 (8.0)
|
<0.001
|
|
Preexisting diabetes mellitus
|
15,169 (1.8)
|
279 (1.8)
|
4,521 (1.4)
|
7,244 (1.8)
|
2,763 (2.9)
|
362 (3.8)
|
<0.001
|
|
Gestational diabetes mellitus
|
81,156 (9.6)
|
1,209 (7.8)
|
29,279 (8.8)
|
38,938 (9.9)
|
10,649 (11.1)
|
1,081 (11.5)
|
<0.001
|
|
Obesity
|
129,690 (15.3)
|
2,024 (13.0)
|
50,493 (15.2)
|
60,967 (15.4)
|
14,463 (15.1)
|
1,744 (18.5)
|
0.05
|
|
Indications for cesarean delivery
|
|
Previous cesarean delivery
|
441,358 (52.0)
|
9,107 (58.6)
|
199,872 (60.1)
|
190,793 (48.3)
|
38,840 (40.5)
|
2,745 (29.1)
|
<0.001
|
|
Fetal malpresentation
|
124,550 (14.7)
|
1,964 (12.6)
|
43,348 (13.0)
|
61,104 (15.5)
|
16,725 (17.4)
|
1,410 (14.9)
|
<0.001
|
|
Fetal hydrocephalus or CNS malformation
|
1,111 (0.1)
|
40 (0.3)
|
293 (0.1)
|
526 (0.1)
|
235 (0.2)
|
17 (0.2)
|
<0.001
|
|
Fetal distress
|
174,619 (20.6)
|
2,946 (19.0)
|
53,565 (16.1)
|
88,441 (22.4)
|
26,365 (27.5)
|
3,301 (35.0)
|
<0.001
|
|
Failed operative delivery
|
4,952 (0.6)
|
64 (0.4)
|
1,350 (0.4)
|
2,522 (0.6)
|
922 (1.0)
|
93 (1.0)
|
<0.001
|
|
Cord prolapse
|
3,981 (0.5)
|
83 (0.5)
|
1,266 (0.4)
|
1,991 (0.5)
|
555 (0.6)
|
86 (0.9)
|
<0.001
|
|
Vasa previa
|
921 (0.1)
|
16 (0.1)
|
156 (0.0)
|
432 (0.1)
|
288 (0.3)
|
30 (0.3)
|
<0.001
|
|
Fetal–maternal disproportion
|
23,692 (2.8)
|
355 (2.3)
|
8,810 (2.6)
|
11,362 (2.9)
|
2,839 (3.0)
|
325 (3.4)
|
0.02
|
|
Obstructed labor
|
23,641 (2.8)
|
435 (2.8)
|
8,228 (2.5)
|
11,431 (2.9)
|
3,228 (3.4)
|
319 (3.4)
|
<0.001
|
|
Abnormal forces of labor
|
120,032 (14.1)
|
1,696 (10.9)
|
36,636 (11.0)
|
62,569 (15.8)
|
16,699 (17.4)
|
2,432 (25.8)
|
<0.001
|
|
Long labor
|
9,404 (1.1)
|
126 (0.8)
|
2,858 (0.9)
|
4,633 (1.2)
|
1,579 (1.6)
|
208 (2.2)
|
<0.001
|
|
Failed induction
|
31,444 (3.7)
|
387 (2.5)
|
9,883 (3.0)
|
16,096 (4.1)
|
4,151 (4.3)
|
927 (9.8)
|
<0.001
|
|
Intrauterine growth restriction
|
27,809 (3.3)
|
393 (2.5)
|
8,258 (2.5)
|
13,383 (3.4)
|
5,097 (5.3)
|
678 (7.2)
|
<0.001
|
|
Macrosomia
|
46,608 (5.5)
|
609 (3.9)
|
15,831 (4.8)
|
23,659 (6.0)
|
5,994 (6.2)
|
514 (5.4)
|
<0.001
|
|
HSV infection
|
14,117 (1.7)
|
176 (1.1)
|
4,682 (1.4)
|
7,107 (1.8)
|
1,925 (2.0)
|
228 (2.4)
|
<0.001
|
|
Oligohydramnios
|
28,061 (3.3)
|
372 (2.4)
|
8,883 (2.7)
|
14,102 (3.6)
|
4,140 (4.3)
|
565 (6.0)
|
<0.001
|
|
Other fetal anomalies
|
2,387 (0.3)
|
27 (0.2)
|
807 (0.2)
|
1,143 (0.3)
|
371 (0.4)
|
39 (0.4)
|
<0.001
|
|
Vaginal anomalies
|
383 (0.0)
|
(0.0)[a]
|
134 (0.0)
|
194 (0.0)
|
45 (0.0)
|
(0.1)[a]
|
0.58
|
|
Outcomes
|
|
Any readmission within 30 d
|
14,059 (1.7)
|
223 (1.4)
|
4,680 (1.4)
|
6,805 (1.7)
|
1,942 (2.0)
|
409 (4.3)
|
<0.001
|
|
Total inpatient charges ($1,000s)
|
25.6 (19.5)
|
23.1 (81.7)
|
23.4 (13.3)
|
26.1 (15.4)
|
30.3 (21.3)
|
44.4 (39.4)
|
<0.001
|
|
Total inpatient costs ($1,000s)
|
6.8 (6.2)
|
6.2 (34.5)
|
6.1 (3.5)
|
6.9 (3.9)
|
8.4 (5.2)
|
11.7 (9.2)
|
<0.001
|
Abbreviations: CNS, central nervous system; HSV, herpes simplex virus.
Note: p-Values by weighted linear regression for continuous variables and weighted chi-square
test for binary/categorical variables. Missing values in charges and costs (27 observations
each).
a ≤ = 10; exact value suppressed due to privacy protections from data supplier.
When patients were stratified by length of stay following cesarean delivery ([Table 1]), shorter hospital stays were associated with younger age (mean age 29.3 for 2-day
stays and 31.1 for 4-day stays), insurance coverage by Medicaid rather than private
insurance, and lower rates of most comorbid conditions. Patients with shorter stays
were also more likely to have had a prior cesarean section (60.1% of those hospitalized
for 2 days and 40.5% of those hospitalized for 4 days). Shorter hospital stays were
more common at government-owned or private for-profit hospitals than private nonprofit
hospitals and were also more common at nonteaching hospitals in both metropolitan
and nonmetropolitan settings. The ZIP code median income of patients hospitalized
for 2 days after cesarean section was lower than patients hospitalized for 4 days.
In unadjusted analyses, shorter hospital stays were associated with lower rates of
readmission, lower total hospital charges, and lower total hospital costs. After regression
modeling for the other measured possible predictors of 2-day discharge, several predictors
were associated with length of stay following cesarean delivery ([Table 2]). Predictors associated with greater probability of discharge within 2 days postsurgery
included other insurance status (compared with privately insured patients), receipt
of care in a nonmetropolitan hospital (compared with a metropolitan, nonteaching hospital),
prior cesarean delivery, and tobacco use disorder. Factors associated with lower probability
of 2-day or earlier discharge included increasing age, coverage with Medicare or Medicaid,
care in a nonprofit hospital (vs. a government hospital), receipt of care in a metropolitan,
teaching hospital (vs. a metropolitan, nonteaching hospital), increasing ZIP code-level
median household income (vs. decreasing in the unadjusted results), most comorbid
conditions, and most indications for cesarean delivery other than history of prior
cesarean delivery.
Table 2
Adjusted predictors of a 2-day or shorter hospital stay following cesarean delivery
|
Relative risk (95% confidence interval)
|
|
Age in y at admission
|
0.99[a] (0.98, 0.99)
|
|
Primary payer (vs. private)
|
|
Medicare
|
0.75[a] (0.68, 0.82)
|
|
Medicaid
|
0.88[a] (0.85, 0.91)
|
|
Self-pay
|
1.07 (0.98, 1.17)
|
|
No charge
|
0.77 (0.52, 1.14)
|
|
Other
|
1.08[b] (1.02, 1.15)
|
|
Control/ownership of hospital (vs. government, nonfederal)
|
|
Private, nonprofit
|
0.81[a] (0.72, 0.90)
|
|
Private, investor-owned
|
0.95 (0.83, 1.09)
|
|
Teaching status of urban hospitals (vs. metropolitan, nonteaching)
|
|
Metropolitan teaching
|
0.80[a] (0.74, 0.87)
|
|
Nonmetropolitan hospital
|
1.21[a] (1.12, 1.32)
|
|
Bed size of hospital (vs. small)
|
|
Medium
|
0.95 (0.86, 1.04)
|
|
Large
|
0.93 (0.84, 1.02)
|
|
Zip code median household income ($1,000s) (vs. $1–43.9)
|
|
$44.0–55.9
|
0.95[c] (0.91, 0.98)
|
|
56.0–73.9
|
0.85[a] (0.81, 0.89)
|
|
74.0+
|
0.69[a] (0.63, 0.76)
|
|
Number of patients at facility in cohort
|
1.00[b] (1.00, 1.00)
|
|
Comorbid conditions
|
|
Placenta previa
|
0.81[a] (0.77, 0.86)
|
|
Gestational hypertension
|
0.85[a] (0.83, 0.87)
|
|
Preexisting hypertension
|
0.92[a] (0.89, 0.95)
|
|
Systemic lupus erythematosus
|
0.88[b] (0.79, 0.98)
|
|
Human immunodeficiency virus
|
0.70[a] (0.59, 0.83)
|
|
Drug Abuse
|
0.79[a] (0.75, 0.83)
|
|
Alcohol abuse
|
0.97 (0.83, 1.14)
|
|
Tobacco use
|
1.18[a] (1.14, 1.21)
|
|
Asthma
|
0.89[a] (0.86, 0.92)
|
|
Preexisting diabetes mellitus
|
0.78[a] (0.75, 0.82)
|
|
Gestational diabetes mellitus
|
0.94[a] (0.92, 0.96)
|
|
Obesity
|
1.01 (0.98, 1.05)
|
|
Indications for cesarean delivery
|
|
Previous cesarean delivery
|
1.29[a] (1.26, 1.32)
|
|
Fetal malpresentation
|
0.95[a] (0.93, 0.97)
|
|
Fetal hydrocephalus or CNS malformation
|
0.86 (0.73, 1.01)
|
|
Fetal distress
|
0.88[a] (0.85, 0.90)
|
|
Failed operative delivery
|
0.84[a] (0.78, 0.91)
|
|
Cord Prolapse
|
0.93[b] (0.87, 0.99)
|
|
Vasa previa
|
0.57[a] (0.47, 0.69)
|
|
Fetal–maternal disproportion
|
0.98 (0.94, 1.03)
|
|
Obstructed labor
|
0.95[b] (0.91, 1.00)
|
|
Abnormal forces of labor
|
0.87[a] (0.85, 0.89)
|
|
Long labor
|
0.95 (0.90, 1.01)
|
|
Failed induction
|
0.94[a] (0.91, 0.97)
|
|
Intrauterine growth restriction
|
0.80[a] (0.77, 0.83)
|
|
Macrosomia
|
0.92[a] (0.90, 0.95)
|
|
HSV infection
|
0.89[a] (0.84, 0.93)
|
|
Oligohydramnios
|
0.91[a] (0.88, 0.94)
|
|
Other fetal anomalies
|
1.01 (0.92, 1.11)
|
|
Vaginal anomalies
|
0.97 (0.80, 1.19)
|
Abbreviation: CNS, central nervous system; HSV, herpes simplex virus.
a
p < 0.001.
b
p < 0.05.
c
p < 0.01.
There was significant facility variation in the duration of stay following cesarean
delivery ([Table 1], [Fig. 2]). [Fig. 2A] depicts the number of hospitals (as a percentage) that discharged patients on postoperative
day 2 or sooner, when expressed as a percentage of their total postcesarean discharges.
The median facility discharged 47.2% of patients within 2 days of delivery, with the
25th percentile 23.8 and the 75th percentile 71.3%. [Fig. 2B] shows the distribution of hospitals according to average length of stay in days.
The overall mean length of stay was 2.6 days, with 25th percentile 2.3 days and 75th
percentile 2.9 days.
Fig. 2 (A) Facility variation in the percentage of patients discharged at or before postoperative
day 2. Graph depicts the number of hospitals (as a percentage) that discharge patients
on postoperative day 2 or sooner, when expressed as a percentage of their total postcesarean
discharges. (B) Facility variation in average length of stay in days.
When facilities were stratified into quartiles by percentage of patients discharged
on day 2 or sooner ([Table 3]), patients treated at facilities with the highest rate were younger, more likely
to be covered by Medicaid, lived in ZIP codes with lower median household incomes,
and were more likely to have had a prior cesarean section. The hospitals were more
likely to be government, nonteaching or nonmetropolitan hospitals, and to have had
fewer cases included in the cohort. Rates of placenta previa, drug abuse, and asthma
were lower in these facilities with higher rates of 2-day discharge, whereas rates
of tobacco use were higher.
Table 3
Baseline patient and facility characteristics, stratified by facility percentage of
patients discharged within 2 days of cesarean delivery
|
Percentage of patients discharged in 2 d or less (quartiles)
|
|
Overall
(N = 456,312) (weighted N = 848,556)
|
0.0–17.8%
(N = 114,377)
(weighted N = 200,456)
|
17.8–38.1%
(N = 114,344)
(weighted N = 225,166)
|
38.2–63.3%
(N = 113,865)
(weighted N = 217,095)
|
63.3–100.0%
(N = 113,726)
(weighted N = 205,839)
|
p-Value
|
|
Mean (standard deviation) or %
|
|
Age in y at admission
|
29.9 (5.7)
|
31.3 (5.8)
|
30.1 (5.4)
|
29.5 (5.6)
|
28.6 (5.8)
|
<0.001
|
|
Primary payer
|
|
Medicare
|
7,953 (0.9)
|
2,382 (1.2)
|
1,598 (0.7)
|
2,332 (1.1)
|
1,641 (0.8)
|
<0.001
|
|
Medicaid
|
349,491 (41.2)
|
74,611 (37.2)
|
86,208 (38.3)
|
89,829 (41.4)
|
98,843 (48.0)
|
|
Private
|
457,887 (54.0)
|
118,128 (58.9)
|
128,041 (56.9)
|
115,713 (53.3)
|
96,004 (46.6)
|
|
Self-pay
|
10,281 (1.2)
|
2,469 (1.2)
|
2,544 (1.1)
|
2,653 (1.2)
|
2,615 (1.3)
|
|
No charge
|
416 (0.0)
|
105 (0.1)
|
138 (0.1)
|
99 (0.0)
|
74 (0.0)
|
|
Other
|
22,529 (2.7)
|
2,761 (1.4)
|
6,637 (2.9)
|
6,470 (3.0)
|
6,662 (3.2)
|
|
Control/ownership of hospital
|
|
Government, nonfederal
|
92,418 (10.9)
|
16,347 (8.2)
|
16,698 (7.4)
|
21,333 (9.8)
|
38,040 (18.5)
|
<0.001
|
|
Private, nonprofit
|
645,943 (76.1)
|
171,214 (85.4)
|
179,074 (79.5)
|
170,145 (78.4)
|
125,511 (61.0)
|
|
Private, investor-owned
|
110,195 (13.0)
|
12,894 (6.4)
|
29,395 (13.1)
|
25,617 (11.8)
|
42,289 (20.5)
|
|
Teaching status of urban hospitals
|
|
Metropolitan nonteaching
|
186,918 (22.0)
|
27,030 (13.5)
|
46,844 (20.8)
|
53,150 (24.5)
|
59,894 (29.1)
|
<0.001
|
|
Metropolitan teaching
|
578,867 (68.2)
|
170,728 (85.2)
|
165,877 (73.7)
|
141,216 (65.0)
|
101,047 (49.1)
|
|
Nonmetropolitan hospital
|
82,771 (9.8)
|
2,698 (1.3)
|
12,445 (5.5)
|
22,730 (10.5)
|
44,898 (21.8)
|
|
Bed size of hospital
|
|
Small
|
137,589 (16.2)
|
25,635 (12.8)
|
41,247 (18.3)
|
31,005 (14.3)
|
39,702 (19.3)
|
0.01
|
|
Medium
|
251,640 (29.7)
|
50,317 (25.1)
|
81,885 (36.4)
|
52,564 (24.2)
|
66,874 (32.5)
|
|
Large
|
459,327 (54.1)
|
124,504 (62.1)
|
102,035 (45.3)
|
133,526 (61.5)
|
99,263 (48.2)
|
|
Zip code median household income ($1,000s)
|
|
1–43.9
|
235,253 (27.7)
|
38,894 (19.4)
|
49,728 (22.1)
|
64,500 (29.7)
|
82,131 (39.9)
|
<0.001
|
|
44.0–55.9
|
232,559 (27.4)
|
39,659 (19.8)
|
58,486 (26.0)
|
69,084 (31.8)
|
65,330 (31.7)
|
|
56.0–73.9
|
205,889 (24.3)
|
49,081 (24.5)
|
65,953 (29.3)
|
52,706 (24.3)
|
38,150 (18.5)
|
|
74.0+
|
174,855 (20.6)
|
72,822 (36.3)
|
50,999 (22.6)
|
30,805 (14.2)
|
20,228 (9.8)
|
|
Number of patients at facility in cohort
|
717.1 (775.3)
|
1,042.3 (1,201.8)
|
652.0 (478.0)
|
759.4 (730.3)
|
427.0 (347.3)
|
<0.001
|
|
Comorbid conditions
|
|
Placenta previa
|
9,038 (1.1)
|
2,625 (1.3)
|
2,404 (1.1)
|
2,200 (1.0)
|
1,809 (0.9)
|
<0.001
|
|
Gestational hypertension
|
58,809 (6.9)
|
13,156 (6.6)
|
16,027 (7.1)
|
15,674 (7.2)
|
13,952 (6.8)
|
0.13
|
|
Preexisting hypertension
|
28,547 (3.4)
|
6,043 (3.0)
|
7,427 (3.3)
|
7,891 (3.6)
|
7,186 (3.5)
|
0.01
|
|
Systemic lupus erythematosus
|
1,226 (0.1)
|
358 (0.2)
|
330 (0.1)
|
314 (0.1)
|
223 (0.1)
|
0.003
|
|
Human immunodeficiency virus
|
1,300 (0.2)
|
286 (0.1)
|
370 (0.2)
|
370 (0.2)
|
274 (0.1)
|
0.76
|
|
Drug abuse
|
21,348 (2.5)
|
3,695 (1.8)
|
5,427 (2.4)
|
5,691 (2.6)
|
6,536 (3.2)
|
<0.001
|
|
Alcohol abuse
|
1,038 (0.1)
|
214 (0.1)
|
293 (0.1)
|
251 (0.1)
|
280 (0.1)
|
0.48
|
|
Tobacco use
|
50,069 (5.9)
|
6,603 (3.3)
|
13,033 (5.8)
|
14,491 (6.7)
|
15,942 (7.7)
|
<0.001
|
|
Asthma
|
45,630 (5.4)
|
12,275 (6.1)
|
12,758 (5.7)
|
11,482 (5.3)
|
9,114 (4.4)
|
<0.001
|
|
Preexisting diabetes mellitus
|
15,169 (1.8)
|
3,476 (1.7)
|
4,128 (1.8)
|
4,101 (1.9)
|
3,464 (1.7)
|
0.32
|
|
Gestational diabetes mellitus
|
81,156 (9.6)
|
19,999 (10.0)
|
22,077 (9.8)
|
20,221 (9.3)
|
18,860 (9.2)
|
0.02
|
|
Obesity
|
129,690 (15.3)
|
26,900 (13.4)
|
34,609 (15.4)
|
35,823 (16.5)
|
32,359 (15.7)
|
0.03
|
|
Indications for cesarean delivery
|
|
Previous cesarean delivery
|
441,358 (52.0)
|
100,948 (50.4)
|
118,018 (52.4)
|
113,746 (52.4)
|
108,646 (52.8)
|
<0.001
|
|
Fetal malpresentation
|
124,550 (14.7)
|
30,743 (15.3)
|
34,697 (15.4)
|
30,939 (14.3)
|
28,171 (13.7)
|
<0.001
|
|
Fetal hydrocephalus or CNS malformation
|
1,111 (0.1)
|
287 (0.1)
|
290 (0.1)
|
375 (0.2)
|
159 (0.1)
|
0.03
|
|
Fetal distress
|
174,619 (20.6)
|
46,727 (23.3)
|
45,055 (20.0)
|
43,250 (19.9)
|
39,588 (19.2)
|
<0.001
|
|
Failed operative delivery
|
4,952 (0.6)
|
1,209 (0.6)
|
1,438 (0.6)
|
1,144 (0.5)
|
1,161 (0.6)
|
0.16
|
|
Cord prolapse
|
3,981 (0.5)
|
901 (0.4)
|
1,059 (0.5)
|
1,036 (0.5)
|
985 (0.5)
|
0.88
|
|
Vasa previa
|
921 (0.1)
|
299 (0.1)
|
271 (0.1)
|
230 (0.1)
|
121 (0.1)
|
<0.001
|
|
Fetal–maternal disproportion
|
23,692 (2.8)
|
3,972 (2.0)
|
6,642 (2.9)
|
5,939 (2.7)
|
7,139 (3.5)
|
<0.001
|
|
Obstructed labor
|
23,641 (2.8)
|
5,332 (2.7)
|
6,559 (2.9)
|
5,495 (2.5)
|
6,255 (3.0)
|
0.06
|
|
Abnormal forces of labor
|
120,032 (14.1)
|
30,622 (15.3)
|
32,059 (14.2)
|
29,624 (13.6)
|
27,727 (13.5)
|
<0.001
|
|
Long labor
|
9,404 (1.1)
|
2,402 (1.2)
|
2,448 (1.1)
|
2,470 (1.1)
|
2,084 (1.0)
|
0.45
|
|
Failed induction
|
31,444 (3.7)
|
8,125 (4.1)
|
8,136 (3.6)
|
7,998 (3.7)
|
7,186 (3.5)
|
0.08
|
|
Intrauterine growth restriction
|
27,809 (3.3)
|
6,755 (3.4)
|
7,537 (3.3)
|
7,133 (3.3)
|
6,384 (3.1)
|
0.44
|
|
Macrosomia
|
46,608 (5.5)
|
11,144 (5.6)
|
13,090 (5.8)
|
11,800 (5.4)
|
10,574 (5.1)
|
0.05
|
|
HSV infection
|
14,117 (1.7)
|
3,646 (1.8)
|
3,951 (1.8)
|
3,501 (1.6)
|
3,018 (1.5)
|
0.13
|
|
Oligohydramnios
|
28,061 (3.3)
|
7,538 (3.8)
|
7,063 (3.1)
|
6,886 (3.2)
|
6,575 (3.2)
|
0.001
|
|
Other fetal anomalies
|
2,387 (0.3)
|
690 (0.3)
|
696 (0.3)
|
561 (0.3)
|
439 (0.2)
|
0.17
|
|
Vaginal anomalies
|
383 (0.0)
|
97 (0.0)
|
122 (0.1)
|
86 (0.0)
|
79 (0.0)
|
0.43
|
|
Outcomes
|
|
Any readmission within 30 d
|
14,059 (1.7)
|
3,333 (1.7)
|
3,753 (1.7)
|
3,476 (1.6)
|
3,496 (1.7)
|
0.67
|
|
Total inpatient charges ($1,000s)
|
25.6 (19.5)
|
27.4 (19.3)
|
23.9 (14.7)
|
25.9 (26.4)
|
25.6 (14.9)
|
0.08
|
|
Total inpatient costs ($1,000s)
|
6.8 (6.2)
|
7.5 (4.5)
|
6.5 (3.5)
|
6.8 (10.1)
|
6.5 (4.0)
|
0.001
|
Abbreviation: CNS, central nervous system; HSV, herpes simplex virus.
Note: p-Values by weighted linear regression for continuous variables and weighted chi-square
test for binary/categorical variables. Missing values in charges and costs (27 observations
each).
In unadjusted analyses, facility rates of 2-day or earlier discharge were associated
with no statistically significant difference in 30-day, all-cause readmission (relative
risk: 1.03, 95% confidence interval: 0.91–1.16) ([Fig. 3]). After regression adjustment, this difference remained not statistically significant
(relative risk: 1.02, 95% confidence interval: 0.90–1.16). This corresponds to an
absolute risk difference of 0.04% (95% confidence interval: −0.17 to 0.24%). These
findings were robust to other specifications of the facility variation (changing functional
form to use squared term, quartiles, or restricted cubic spline), specification using
mean length of stay rather than percentage discharged in 2 days or less, and for readmission,
use of a 42-day time frame rather than a 30-day time frame. The facility rate of discharge
was associated with lower inpatient costs in both unadjusted (percentage reduction:
17%, 95% confidence interval: 8–25%) and adjusted models (percentage reduction: 15%;
95% confidence interval: 6–23%). This corresponds to an average incremental cost difference
of $111 (95% confidence interval: −181 to −41).
Fig. 3 Unadjusted association between facility-level rate of discharge within 2 days of
cesarean delivery and 30-day, all-cause readmission rate. Facilities are classified
along the X-axis according to the percentage of their patients that are discharged within 2 days
of cesarean. The 30-day readmission rates are expressed as percentage with 95% confidence
intervals.
Discussion
In this retrospective cohort study in a large population of low-risk patients undergoing
cesarean deliveries uncomplicated by either high-risk comorbid conditions or incidence
of maternal morbidity, virtually all patients were discharged home on postoperative
day 2, 3, or 4. There was broad facility variation in the percentage of patients discharged
home on day 2 or earlier, which could not be explained by patient or hospital characteristics.
After regression adjustment, rates of postoperative day 2 or earlier discharge were
not associated with rates of all-cause 30-day readmission but were associated with
lower costs.
This study evaluated risk factors to further explore differences in length of stays
less than 4 days after cesarean delivery in the United States, whereas previous studies
focused primarily on length of discharge more than 4 days[11] or did not focus specifically on cesarean deliveries.[12] We found within our low-risk cohort that in general, younger patients with fewer
comorbidities and a history of prior cesarean delivery were more likely to be discharged
in 2 days or less, which was an expected finding. History of cesarean delivery was
a positive predictor of 2-day discharge, whereas most of the cesarean indications
suggestive of labored cesarean section (such as failed induction or abnormal forces
of labor) were negative predictors of 2-day discharge. This provides indirect evidence
that patients presenting for scheduled cesarean delivery appear more likely to have
2-day discharge when compared with those having unlabored cesarean deliveries. There
were interesting intersections between insurance status and ZIP code-level income
in that after adjustment, Medicaid recipients were less likely to be discharged home on the second hospital day, while patients from lower
income ZIP codes were more likely to be discharged home on the second hospital day. This discrepancy may reflect
differences in the unit of measurement (individual patients vs. ZIP code), or more
interactions between income and insurance carrier (e.g., that patients who are covered
by Medicaid in high-income ZIP codes differ from those residing in low-income ZIP
codes). Further research with individual-level income and insurance data would be
needed to clarify this dynamic.
Prior studies on length of stay have focused on effects of early discharge and risk
factors for early discharge. A 2002 Cochrane review indicated no difference in infant
readmission for an early postnatal discharge and no pooled difference in maternal
readmissions, although definitions of early discharge varied widely and most included
patients with vaginal rather than cesarean deliveries.[13] An observational study in Egypt also noted no difference in maternal hospital readmissions
if patients were discharged at 24 versus 72 hours following cesarean section.[14] These studies are in accord with our findings of no increased rate of readmission
within 30 days based on length of stay. In contrast, a Canadian study in 2002 reported
increased maternal readmissions with length of stays less than 4 days, when compared
with 5 days.[15] We note the difference in using 4 versus 2 days as the breakpoint in their analysis
when compared with our own. Given that postpartum readmissions in general are rare
in the United States, occurring in only 1.01% of all patients, and only 1.7% in our
low risk, cesarean delivery only sample, it may be more difficult to find significant
differences in readmission rates.[16] From a global perspective, a review of length of stay after cesarean delivery in
92 low- to middle-income countries described large variability with mean lengths of
stay of 2.5 to 9.3 days.[17]
The significant variation in postcesarean length of stay at the facility level in
this study is consistent with an extensive body of literature in the United States
documenting geographic and provider-level variations in care.[6]
[18] In the case of length of stay after an uncomplicated cesarean delivery, based on
our anecdotal experiences in different facilities, we suspect that a component of
the facility-level variation may reflect an ingrained institutional habit (i.e., “how
we have always done this”) in terms of when discharge is offered to patients. Our
results should provide some reassurance that in a subset of low-risk patients, high
facility-level rates of discharge within 2 days of cesarean delivery was not associated
with readmissions. These results suggest that offering discharge on postoperative
day 2, or discharging patients on postoperative day 2 on their request, may be reasonable
in appropriately selected patients.
This study's results were enhanced by several strengths. The use of the 2017 NRD provides
a large, contemporary sample of more than 50% of all U.S. hospitalizations and more
than 1,500 facilities. This is a large sample, designed for use in generating nationally
representative estimates of readmissions. The NRD includes both patient and facility
factors, providing a diverse set of variables for consideration in analysis. However,
as with all analyses, this study included weaknesses as well. The use of administrative
data significantly limits the quality of covariate adjustment available, and the potential
for confounding cannot be excluded. This analysis was deliberately limited to a small
low-risk subset of all cesarean deliveries and does not reflect patients with high-risk
features such as pregnancy-related hypertensive disorders or diabetes. We could not
assess neonatal outcomes, including neonatal readmission, which is an important consideration
in early maternal discharge. Cost data were generated by facility-wide cost-to-charge
ratios rather than department-specific ratios, and are thus potentially less accurate,
and reflect the hospital fees alone (do not reflect professional fees such as obstetrics
and anesthesiology services). The use of ZIP code-level income has been found to be
suboptimal, given the significant variation in income across many ZIP codes.[19] Furthermore, other important considerations play a role in discharge timing after
a cesarean delivery, including effective pain control, need for social services, breastfeeding,
and postpartum education, which were not addressed in this study.
In conclusion, in this analysis of low-risk cesarean deliveries in the United States,
significant variation in practice patterns existed in postcesarean section length
of stay even after statistical adjustment. This variation was not associated with
significant differences in 30-day readmission rates but was associated with lower
total inpatient costs. Further study is necessary to better characterize postoperative
processes of care, identification of which patients may be candidates for earlier
discharge, and the implications of earlier discharge on maternal and neonatal health,
economics, and patient satisfaction.
