Guide to Avoiding Unnecessary Cesarean Sections in New York – Factors

April 21, 2010

Sidney Wolfe, M.D.
Public Citizen Health Research Group

Full report as a pdf
Statements from press conference

Introduction
Objectives
Methods
About New York
Variations in Cesarean Sections, VBACs, and Midwife Availability by County and by Hospital Within Each County
Healthy Outliers: Two New York Hospitals that Have Bucked the Trend
Factors Possibly Associated with Variation in Rates
What is Driving Cesareans in New York?
How a Woman Can Avoid an Unnecessary Cesarean in New York State
What Health Departments and Hospitals Can Do to Reduce Unnecessary Cesareans
New York Hospital Birth Statistics by County

Factors Possibly Associated With Variation in Rates

In this section, we examine factors that might explain differences in cesarean rates, such as the level of perinatal care and the size of the hospital. As will be seen below, neither of these factors nor do socio-economic factors begin to explain the enormous differences from hospital to hospital in New York State and among counties.

Cesareans by Level

Overall Cesarean Rate and Level of Care
Table 3 summarizes the overall cesarean section rate by level of perinatal care in the hospital. As expected, the average cesarean section rate rises with level of perinatal care: The highest rate (35.4 percent) is found among the Regional Perinatal Center and the lowest rate (32.0 percent) is among Level 1 hospitals, which provide routine care and do not operate NICUs.

Nevertheless, the rise is not consistent: Level 2 hospitals have a slightly higher overall cesarean rate (34.3 percent vs. 34.0 percent) than Level 3 hospitals, which are designed to care for higher-risk patients and are more technology-intensive. What is surprising is that there is not a steeper gradient between the RPCs and the more community-oriented hospitals, which serve a smaller catchment area and are designed for routine care. This may be the result of smaller hospitals preferring to schedule deliveries to avoid being short-staffed and unable to meet the demands of spontaneous deliveries.

Even within a given level of care, the rate of cesarean section can vary markedly from one hospital to another. Among the RPCs, for example, cesarean rates range from a low of 20.9 percent (Maimonides Medical Center, in Brooklyn) to a high of 47.5 percent (Westchester Medical Center, in Valhalla), a more than 2.2-fold difference.

Within the other levels of care, the variation is similar or higher. Table 3 indicates averages and ranges of cesarean section rates within each level. The variation is more than three-fold for Level 1, 2.8-fold for Level 2, and 2.2-fold for Level 3.

Table 3: Average and Range of Cesarean Section Rates by Perinatal Level of Care, New York State: 2007

Level of Care	Number of Hospitals	Cesarean % (Range)
Level 1	59	32.0% (16.6-53.3)
Level 2	25	34.3% (18.5-52.7)
Level 3	36	34.0% (20.7-49.1)
Regional	18	35.4% (20.9-47.5)
Total*	138	34.1%

* Only includes hospitals that have been assigned perinatal levels

Primary Cesarean Rate and Level of Care
Primary cesarean rates rise consistently with level of perinatal care: They are lowest among Level 1 hospitals and increase gradually for Level 2 and Level 3 institutions, with RPCs having the highest rate. The gradient, however, is not steep: The rate rises from 18.0 percent for Level 1 institutions, which lack NICUs, to 22.8 percent for fully-equipped RPCs.

VBAC Rate and Level of Care
As can be expected, there is a direct relationship between VBACs and level of perinatal care: The rate rises consistently with an increase in the level of care. The rate of 7.05 percent among Level 1 facilities increased to 11.4 percent among the RPCs.

Among the RPCs, however, there is more variation within the level than there is between one level and another: The VBAC rate at the Regional Perinatal Centers ranged from a low of 5.13 percent (North Shore University Hospital, Nassau County) to a high of 30.1 percent (Maimonides Medical Center, Kings County).

Table 4. Rate and Ranges of VBACs by Level of Care, New York State: 2007

Level of Care	Number of Hospitals	VBAC % (Range)
Level 1	59	7.1% (0.0-34.4)
Level 2	25	7.75% (0.6-30.9)
Level 3	36	9.40% (0.0-28.1)
Regional	18	11.37% (0.3-30.1)
Total	138	9.25% (0.0-34.4)

* Only includes hospitals that have been assigned perinatal levels

Cesareans by Size of Hospital

Overall Cesarean Rate and Size of Hospital
Contrary to expectation, the largest hospitals do not have the highest cesarean section rates, nor is there a consistent relationship between size of hospital and rate of cesarean section. The rate varies across a range, from 25.9 percent for those with 700-799 beds to 38.8 percent for those with 600-699 beds. Because some smaller hospitals may not have the resources to handle complicated deliveries, they may be expected to refer higher-risk mothers to larger facilities that are better staffed and equipped to handle potential complications. If this were happening, smaller hospitals would have lower cesarean section rates. But this is not the case in New York. Hospitals with fewer than 100 beds have cesarean section rates that are not dissimilar to those for much larger institutions, as shown in Table 5.

Table 5: Rate and Range of Cesarean Section by Size of Hospital in Number of Beds, New York State: 2007

Number of Beds	Number of Hospitals	Cesarean % (Range)
1-49	5	32.5% (27.9-36.5)
50-99	18	33.8% (16.6-53.3)
100-199	29	30.7% (20.4-46.8)
200-299	30	34.8% (18.5-52.7)
300-399	20	33.9% (21.2-49.0)
400-499	14	34.3% (20.7-49.1)
500-599	12	33.8% (23.6-44.4)
600-699	4	38.8% (30.5-47.5)
700-799	3	25.9% (20.9-35.5)
800+	8	36.4% (27.3-53.3)
Total	143	34.1% (16.6-53.3)

A national study done in 2004 found that rural hospitals had slightly higher rates of cesarean sections. This was attributed to rural facilities, especially small ones, relying on surgical delivery because they lack the resources to handle VBACs. Moreover, small hospitals may lack the staff to provide emergency care and may therefore opt to schedule a cesarean section rather than risk having a woman deliver at a time when the facility is understaffed. A similar phenomenon may explain the relatively high rate of cesareans among small hospitals in New York State.

Primary Cesarean Rate and Size of Hospital

Table 6: Rate of Primary Cesarean Section by Size of Hospital, New York State: 2007

Number of beds	Number of hospitals	Primary Cesarean % (Range)
1-49	5	22.1% (17.5-25.7)
50-99	18	23.1% (9.9-38.6)
100-199	29	20.7% (13.2-34.6)
200-299	30	24.3% (12.0-40.3)
300-399	20	23.9% (12.2-37.5)
400-499	14	24.4% (12.2-38.6)
500-599	12	24.9% (14.6-34.3)
600-699	4	30.3% (24.4-35.5)
700-799	3	18.6% (14.9-25.7)
800+	8	28.4% (19.3-34.8)
Total	143	24.6% (9.9-40.3)

As with the overall cesarean rate, there is no consistent relationship between primary cesarean rate and the size of the hospital.

VBAC Rate and Size of Hospital

As with level of care, there is a general tendency for the rate of VBACs to rise with the size of hospital, but the data are not entirely consistent. The VBAC rate is 3.1 percent for the smallest hospitals, and it increases with hospital size until it reaches 8.2 percent among those with 200-299 beds. After that, the rate dips to 7.1 percent, after which it again rises with size to 22.2 percent as the number of beds increases from those with 300-399 beds to those with 800 beds. At the top of the scale, however, the trend is reversed: Hospitals with more than 800 beds have a lower VBAC rate, 11.4 percent. These are a very distinctive subsample of hospitals: In addition to their larger size and greater complexity, they are located in New York City and its suburbs, and they are teaching hospitals.

Table 7. Rate and Range of VBACs, by Size of Hospital, New York State: 2007

Number of beds	Number of hospitals	VBAC % (Range)
1-49	5	3.1% (0.0-10.0%)
50-99	18	5.9% (0.0-22.9)
100-199	29	7.0% (0.0-34.4)
200-299	30	8.2% (0.0-30.9)
300-399	20	7.1% (0.3-23.9)
400-499	14	7.9% (0.0-22.3)
500-599	12	9.9% (0.6-21.9)
600-699	4	12.5% (9.4-18.6)
700-799	3	22.2% (11.3-30.0)
800+	8	11.4% (5.1-21.4)
Total	143	9.3% (0.0-34.4)

Overall Cesarean Rates and Other Variables

Large variations in county- or hospital-specific rates are also not explained by socio-economic conditions measured by county median income, the percentage of deliveries paid for by Medicaid or by the proportion of births by midwives.

When we did a statistical analysis of how cesareans vary by county median income, we found a negligible association between the two (R squared = .08), meaning that this factor could explain only eight percent of the variation in cesarean rates. The relationship between hospital cesarean rate and Medicaid reimbursement was slightly negative, in that the rate decreased with an increasing proportion of births paid by Medicaid. But here, too, this factor only accounted for a small proportion (12.7 percent) of the variation in rates.

We also examined the overall cesarean rate as a function of births attended by midwives for hospitals that provide this service. The relationship between the two was negative: The higher the proportion of births assisted by midwives, the lower the cesarean rate. This is as expected, because cesareans exclude certified midwives as primary attendants. Although the relationship was stronger than that for median income or Medicaid reimbursement, only 18.5 percent of the variation in hospital-specific rates is explained by differences in midwifery practices. This is nevertheless stronger than the correlation found nationally between the rate of cesarean births by state and the overall rate of midwife-attended births in 2005.[2]