Cesarean Rates Vary Ten-fold Among US Hospitals; Reducing Variation May Address Quality & Cost Issues

by faithgibson on March 18, 2013

in Contemporary Childbirth Politics

2013 Project HOPE—The People-to-People Health Foundation, Inc.
doi: 10.1377/hlthaff.2012.1030 HEALTH AFFAIRS 32, NO. 3 (2013): 527–535,

By Katy Backes Kozhimannil, Michael R. Law, and Beth A. Virnig

QUOTE: In the context of childbirth, better care co-ordination could include more effective risk- based triage for maternity care. Such triage could take the form of high-risk hospitals with the capacity to manage extremely complex patients alongside obstetric care settings, such as licensed birth centers, which focus on physiologic childbirth for lower-risk women.


ABSTRACT Cesarean delivery is the most commonly performed surgical procedure in the United States, and cesarean rates are increasing. Working with 2009 data from 593 US hospitals nationwide, we found that cesarean rates varied tenfold across hospitals, from 7.1 percent to 69.9 percent. Even for women with lower-risk pregnancies, in which more limited variation might be expected, cesarean rates varied fifteen-fold, from 2.4 percent to 36.5 percent.

Thus, vast differences in practice patterns are likely to be driving the costly overuse of cesarean delivery in many US hospitals. Because Medicaid pays for nearly half of US births, government efforts to decrease variation are warranted. We focus on four promising directions for reducing these variations, including better coordinating maternity care, collecting and measuring more data, tying Medicaid payment to quality improvement, and enhancing patient-centered decision making through public reporting.

SOURCE:  Authors’ calculations based on data from the 2009 Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project (HCUP).

  • (a) Hospital bed-size categories are defined by HCUP, based on number of short-term acute hospital beds, and are specific to the hospital’s US region, rural-urban designation, and teaching status. Bed-size information is missing for thirteen hospitals.
  • (b) Hospital teaching status was obtained by HCUP from the American Hospital Association Annual Survey of Hospitals.
  • (c) Classification of urban or rural hospital location used Core Based Statistical Area codes based on 2000 census data.
  • (d) IQR (InterQuartile Range) is calculated as the difference between the 75th and 25th percentiles.
  • (e) The lower-risk cesarean delivery rate is calculated as the percentage of cesarean deliveries among women with term, singleton, vertex pregnancies and no history of cesarean delivery.

==============synopsis & excerpts ========================

The study’s final data set included 817,318 deliveries that occurred in 2009 at 593 different hospitals.

Recognizing that unadjusted cesarean rates probably differ across hospitals because of differences in patient populations, we also cal- culated hospital-specific rates of cesarean delivery among women who were at lower risk for cesarean delivery.

To determine which pregnancies were lower risk, we followed the recommen- dations of the American College of Obstetricians and Gynecologists as closely as our data allowed. [13]

Thus, our measure of the lower-risk cesarean delivery rate at each hospital represents the rate of cesarean deliveries for women with term, singleton, and vertex pregnancies (those that are not in breech position) and no history of prior cesarean delivery.  Hospital lower-risk cesarean rates ranged from 2.4 percent to 36.4 percent—a fifteen-fold variation across hospitals.

It was not possible to identify first-time mothers.

Total for hospitals based on size:       rural = 195     small = 131     medium = 179     large = 270      teaching = 142

Mean # of C-sections performed per hospital —> 1,378

Minimum and maximum numbers CS performed annually —> a low of 100 CSs, a high of 11,971 CSs

Average Cesarean rate 32.8%; lowest rate 7.1%; highest rate 69.9% (i.e. 70%)

Average CS rate for lowest risk women

CS rates for the very lowest risk category of CB women:

Mean 12.0; minimum rate 2.4%; maximum rate — 36.4%

Cesarean delivery is the most common operating room procedure performed among all patients in US hospitals, [1] and its use is growing. Cesarean rates increased from 20.7 percent of all deliveries in 1996 to 32.8 per- cent in 2011. [2,3]  In international comparisons, US cesarean rates exceed those for similar coun- tries, without measurable clinical benefit. [4,5]

The rise in the cesarean rate is commonly attributed to several factors, including a higher rate of conditions that may necessitate cesarean delivery—such as multiple gestation, maternal obesity, preterm labor, gestational diabetes, or hypertension—as well as physicians’ concerns about liability and malpractice. [4,6,7]  But evidence indicates that these factors do not fully account for the wide differences in cesarean rates ob- served across states and countries. [8–11]

Cesarean delivery is an important, potentially lifesaving intervention. [12,13]  Although common, cesarean delivery is major abdominal surgery that carries distinct risks compared with vaginal delivery: greater chance of infection, injury,blood clots, and need for emergency hysterectomy.[12–14]  It also can cause persistent pain, compromise the establishment of breast-feeding, and complicate later deliveries. [5–17]

Cesarean delivery is often performed to improve neonatal outcomes and mitigate risk; however, it is associated with a greater risk of asphyxia, respiratory distress, and other pulmonary disorders in infants. [3,18,19]

The widespread use of cesarean delivery has important policy implications. Cesarean delivery is much more costly than vaginal delivery ($12,739 versus $9,048 for private health insur- ers in 2010).20 Adverse outcomes and complica- tions have substantial cost implications for de- livery systems and health insurers, both public and private.[21]

This fact is particularly salient for maternal and neonatal health interventions, as hospital charges for these services exceed those for any other condition.[22]  The state and federal budget impacts are particularly notable, as public insurance programs finance nearly half of all US births: In 2009 state Medicaid programs paid more than $3 billion for cesarean deliveries. [23]

The National Institutes of Health, policy lead- ers, and clinicians have expressed concern over increasing cesarean rates. [24]  For example, a leading obstetrician recently issued a call to curb the “relentless rise” of cesarean deliveries. [6]  Similarly, in its Healthy People 2020 initiative, the Department of Health and Human Services put forth clear, authoritative public health goals recommending a 10 percent reduction in both primary and repeat cesarean rates, from 26.5 percent to 23.9 percent, and from 90.8 percent to 81.7 percent, respectively. [25]

Health care providers, patients, and policy makers recognize that variation in procedure rates is an important indicator of health care quality. Such variation may signal potential underuse or overuse of a service, both of which may be clinically harmful and costly. [26]


Reasons For Variation In Hospital Cesarean Rates Cesarean delivery rates should be expected to vary across hospitals based on patients’clinical conditions and choices, hospital capacity, and degree of obstetric and neonatal care specialization, among other factors. [3,13]  The number of clinical indications for a cesarean has in- creased in recent years. However, these changes alone cannot explain the rising rates.

As a result, more attention has been paid to non-medical determinants of a cesarean delivery. [7,33]  Maternal requests for cesarean delivery may vary across hospital patient populations, but available data suggest that such requests are responsible for a very small percentage of all cesarean deliveries and are not likely drivers of the wide variations we detected. [11]

The striking variation we documented in hospital cesarean rates for lower-risk pregnancies indicates that clinical risk factors probably do not provide a full explanation for these differences across hospitals. Our results are consistent with prior research on variations in cesarean delivery rates, and they indicate that practice patterns [i.e. physician preference and hospital/OB department policies] are a likely driver of variations in delivery mode and ought to be the focus of policy interventions to slow or reverse the rise in cesarean delivery rates overall and to decrease varia- tions across hospitals. [6,9]

There are few documented policy successes in achieving these goals in the current maternity care environment. However, our study and prior research suggest that there is an urgent need to address maternity care quality in general and rising cesarean rates and variations in practice patterns in particular. [6,9,34,35]

Based on emerging evidence and interprofessional dialogue, we are aware of four promising directions for reducing variations in cesarean rates across hospitals. [24,34]  For each of these general directions, we describe specific policy interventions currently under way at federal and state levels. These efforts and any future policy strategies to reduce variations in hospital cesarean rates must be rigorously evaluated for intended and unintended impacts.

!IMPROVE SPECIALIZATION AND TRIAGE FOR MATERNITY CARE: Wide variation in cesarean rates among women with similar clinical condi- tions is medically unwarranted. [12,13] Whether such wide variation in cesarean rates persists across facilities depends in part on whether system- level changes that accompany the Affordable Care Act—accountable care organizations, for example—and the state-level statutes that sup- port cost containment measures—such as the recently passed Improving the Quality of Health Care and Reducing Costs through Increased Transparency, Efficiency, and Innovation Act (Chapter 224, 2012) in Massachusetts—will al- low for bundled payments across settings and providers to encourage coordination of care and health promotion.

In the context of childbirth, better care co-ordination could include more effective risk- based triage for maternity care. Such triage could take the form of high-risk hospitals with the capacity to manage extremely complex patients alongside obstetric care settings, such as licensed birth centers, which focus on physiologic childbirth for lower-risk women.  [36] Better triage may reduce overall cesarean rates, but some rate variation across facilities would remain, although this would be by design rather than happenstance. Indeed, in other areas, such as cardiac care, some have argued that hospital spe- cialization can increase both quality and variability. [37]

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