As noted in a previous Health Affairs Blog post by Katy Kozhimannil and Ezra Golberstein, there is significant variability in cesarean delivery rates across the United States, but this is also true worldwide. Worldwide cesarean delivery rates have come under scrutiny and criticism since the World Health Organization (WHO) suggested in 1985 that the optimal rate should not exceed 10 to 15 percent.
Although currently there is no expert agreement on a single optimal level, a general consensus has emerged that extremely low rates (less than 5 percent) suggest underuse and higher rates (greater than 10-15 percent) suggest overuse. Globally, the average rate sits slightly above that recommended level at 16 percent. However, the mean value masks the underlying variability that exists across countries and the different issues inherent in the variation. Of countries which report at least some cesarean deliveries, the range of use runs from 1 percent (Niger) to 52 percent (Brazil) of live child births.
Middle and High-Income Countries
Cesarean rates in middle and high-income countries have continued to increase over the last decade (most are significantly over 15 percent). The average rate among the Organisation for Economic Co-operation and Development (OECD)-member countries is 26.9 per 100 live births (range: 14.7 to 49.0). Comparatively, the United States has a very high rate of cesarean delivery (31.4 per 100 live births). In Switzerland, for example, cesarean section rates varied in 2010 from less than 20 percent to over 40 percent in a region. Within a region, the rates also varied by hospital. A study in France found more cesarean sections were performed in for-profit hospitals than in public hospitals, which treat more complicated pregnancies, suggesting that financial incentives may also play a role in explaining excess cesarean deliveries.
Significant efforts have been made to understand the variation in rates and to determine an optimal level of cesarean delivery. Appropriate rates are associated with underlying population risk including age and obesity level of the mother and safety of the procedure within the region. Reasons given for the high rates in the US mirror those given across other middle and higher income OECD countries:
- surgical improvements that have decreased the risk of the cesarean delivery procedure
- malpractice concerns
- patient and physician convenience
- demographic shifts in the population, including increasing maternal age and obesity and rise in multiple births resulting from fertility treatments
Lower Income Countries
On the other end of the spectrum, lower income countries report much lower rates suggesting substantial underuse of this potentially life-saving procedure. There are still gains to be made in maternal and infant mortality by increasing access to and use of improved birth technologies, including cesarean delivery. In lower income countries, improvements in newborn and maternal mortality have been observed with an increase in cesarean deliveries.
World experience with cesarean deliveries provides an opportunity for cross-national learning in the use of medical technologies to improve health and lower costs. Cesarean delivery rates at both extremes result in excess health risks for mothers and newborns. In countries where cesarean deliveries are currently below 15 percent, there is an improvement in infant, neonatal and maternal mortality and low birth rate with increases in the cesarean rate. In countries where cesarean deliveries are greater than 15 percent, the increasing rates are not associated with these health improvements and can be associated with harm. In middle and higher income countries, substantial decreases in health risks and costs can be achieved through reduction of unnecessary cesarean deliveries.
Prematurely shifting the focus from the overall rate to the variability obviates the substantial gains in health cost savings that can be achieved from reducing the unnecessary procedures. In a 2010 WHO study of the marginal costs associated with the under and overuse of cesarean deliveries in 137 countries, representing 95 percent of global births, excess (rates above 15 percent) cesarean deliveries were estimated to cost approximately $2.32 billion, while the cost of meeting the global need for countries which underutilize (rates below 10 percent) cesarean deliveries was only $432 million. The excess cost of unnecessary cesarean deliveries represents an opportunity to reduce cost for the total health care system struggling with issues of inequities and resource allocation across populations.
In the United States alone, this study estimated there were 673,047 excess cesarean deliveries in 2008. The additional cost to the health care system from those excess deliveries amounted to $687,167,996, which is more than enough to fund the entire number of necessary cesarean deliveries in underserved countries. Although redistributive efforts are never quite that simple, it is clear that from a global perspective, there are substantial inefficiencies and inequities in delivery of health care services.