Introduction  

A rise in caesarean section (C-section) rates to unprecedented levels has become a global concern. In some areas, the rates are alarmingly high. In Latin America and the Caribbean, C-sections account for 40.5% of all births, a rate that is much higher than the recommendations of 10%–19% of all deliveries.1–3 This raises concerns about potentially medically unnecessary interventions and consequent negative effects on maternal and neonatal morbidity and mortality.4–6 Moreover, the cost of C-section overutilisation in 2008 is estimated to have amounted to US$2.32 billion worldwide.4

C-sections represented 45% of all births in Chile in 2014. The country has a much higher C-section rate relative to other countries: it is the second highest among OECD countries and higher than that of many other Latin American countries.7 Between 2001 and 2014, the C-section rate in Chile rose dramatically from 26% to 45%, while the average C-section rate among OECD countries increased from 20% to 27%.8 9 This makes Chile a particularly interesting case study given both its higher than average levels and rapid increase in caesarean delivery rates. Figure 1 in the online supplementary appendix presents a comparison of C-section rates in Chile with a selection of OECD countries for the period 2001–2014.

The success of efforts to contain steadily increasing C-section rates crucially depends on understanding the driving forces behind them. Some common causes include: advanced maternal age, multiple births, patient socioeconomic characteristics, patient preferences, practice style, malpractice liability and local provider capacity.5 7 10 11 Evidence also suggests that financial incentives for physicians, hospitals and insurance companies play a key role in determining the odds of a C-section. Moreover, private sector health providers are increasingly present around the world, and the provision of care for pregnancies and deliveries are not exempt from this trend.12–14 C-sections are more frequently performed among women with private insurance compared with those with public insurance.15 16 Further, C-sections rates are higher in for-profit hospitals than in non-profit hospitals.17 This is also the case in Chile.18 19 In what follows, we push the analysis of private sector health provision a step further by analysing how the latter interacts with the public insurance system in Chile.

Chile’s healthcare system has two non-complementary health insurance providers: individuals decide between public or a private health insurance. Affiliates of the public system pay 7% of their income as premium and copayments. They can then receive treatment from public providers or selected private providers. In 2014, public insurance covered 75.2% of Chile’s population, while private insurance covered 18.5%. The remaining 6.3% was either not insured or belonged to the police or armed forces.20 Privately insured individuals are mostly adults between the ages of 21 and 45, and are on average wealthier than those with public health insurance.21

We focus on an important feature of the Chilean system: publicly insured individuals can opt to receive healthcare at a selected group of private facilities through a copayment for each service (prices are set each year by the Ministry of Health).22 23 In the particular case of births (and also for a selected set of conditions), patients have access to a voucher system or diagnosis-related group (DRG)-based payment that covers all the costs related to the delivery. The patient is responsible for a copayment of a fixed and known in advance sum. The copayment is 25% in the case of births, and the sum is independent of the mode of delivery.

Almost all births occurring in private hospitals under public insurance are financed through this voucher system. The key characteristic is that only women with a singleton pregnancy can opt into this scheme, by physician prescription at week 37, under the condition that they are free of obstetric and specific medical complications. The voucher does not cover other complications due to mother’s health, prematurity-related complications nor multiple births (these are covered through the regular public insurance scheme).24

The main objective of this paper is to measure the likelihood of birth by C-section at private hospitals for publicly insured women as compared with privately insured women. Our analysis contains three parts. First, we show the variation in C-section rates across hospital types and insurance types over time, and we analyse the contribution of each of these groups into the overall C-section rate. Second, we measure the likelihood of birth by C-section for privately insured women as compared with those publicly insured, and at private hospitals, as compared with public ones. Third, we focus on the sample of births in private hospitals, and analyse the likelihood of C-section delivery for privately insured women as compared with publicly insured ones. We also analyse whether there is evidence suggesting that these differences are driven by medical necessity.

Methods

Results

Public hospitals accounted for 77% of all births throughout the period 2001–2014, and 88% of all births were covered by public insurance. Table 1 provides a complete report of the number of deliveries and percentage of C-sections each year by type of insurance and hospital. Online supplementary appendix table 1 reports descriptive statistics on the working sample. The prevalence of births in private facilities covered by public insurance increased from just 1.6% in 2001 to 20.6% in 2014. Births financed by private insurance at private hospitals also increased, from 10.1% to 14.7%. There simultaneously occurred a decline in the number of deliveries in public hospitals covered by public insurance. Births in public hospitals under private insurance are rare.

As expected, C-section rates in public hospitals for deliveries covered by public insurance are the lowest throughout the entire period. Surprisingly, however, we find that the highest C-section rates are found among deliveries in private facilities covered by public insurance; higher even than those for births covered by private insurance (differences in all years analysed are statistically significant at the 1% level). This has been the case since 2001, and by 2014, the C-section rate for births in private hospitals covered by public insurance rose as high as 77.2%.

To further understand the extent to which publicly insured deliveries in private hospitals have added to the increase in C-sections rates in Chile, in table 2 we report the contribution of four different groups, defined by type of insurance and hospital, to the overall C-section rate. Online supplementary appendix table 2 details the weights used in the computations. Since 2008, C-sections among publicly insured women who delivered in private maternity units have been the greatest contributor to the overall C-section rate in Chile. By 2014, the ‘private hospital under public insurance’ group contributed 52% to the overall weighted C-section rate, while the ‘private insurance’ group, including C-sections performed in public and private hospitals, contributed only 22.3%. The remaining 25.7% was generated by publicly covered C-sections performed in public hospitals.

Table 3 presents results of unadjusted and adjusted ORs of C-section delivery. Using all deliveries between 2001 and 2014 (column 1), the unadjusted ORs for a woman covered by private insurance and of delivering at a private hospital are both above 1 (2.27 and 4.55, respectively). Surprisingly, we find that the adjusted likelihood of having a C-section (column 2) is lower for those privately insured than for those with public insurance (OR 0.71, 95% CI 0.63 to 0.79), while the adjusted likelihood of having a C-section at a private hospital is similar to the unadjusted one (OR 5.29, 95% CI 4.42 to 6.32).

We present the same regressions using only the deliveries that occurred in 2001 and separately, only the deliveries that occurred in 2014, in columns 3–6 of table 3. We find that the adjusted probability of having a C-section among privately insured women relative to that of publicly insured women declined during the period under analysis (OR in 2001 is 1.89, 95% CI 1.6 to 2.23; OR in 2014 is 0.56, 95%, CI 0.48 to 0.64).

We turn our focus to the sample of births in private hospitals and present the odds of C-section for publicly insured women as compared with privately insured women in table 4. Pooling all years under analysis (column 2), among women who delivered in a private hospital, we find that the adjusted likelihood of having a C-section is lower for those privately insured than for those with public insurance: the OR is 0.6 (95% CI 0.56 to 0.65).

We also find a small reduction in the adjusted likelihood of a C-section between 2001 and 2014 (columns 4 and 6), among privately insured women relative to that of publicly insured women (OR in 2001: 0.64, 95% CI 0.59 to 0.7; OR in 2014: 0.56, 95% CI 0.5 to 0.62).

A report of the marginal effects is presented in online technical supplementary appendix table 1.

Table 5 presents the analysis on hospital discharges related to maternal morbidity and mortality. We find no evidence of higher rates of maternal morbidity, miscarriages, labour or delivery complications, nor greater maternal mortality among women with public insurance at private institutions. On the contrary, the bulk of discharges for these conditions (81.4%, 80.1% and 69.2%, respectively) and deaths (87.1%) take place at public hospitals and are covered by public insurance.

We also find that the longest length of stay after delivery among the four groups analysed is that for women at public hospitals covered by public insurance. For deliveries in private hospitals, patients with public insurance have a shorter length of stay than those covered by private insurance (2.5 vs 2.9, p value of the difference <0.0001). A report of the marginal effects is presented in online technical supplementary appendix table 2.

Discussion

We analyse C-section rates using the universe of births in Chile for the period 2001–2014. Our results show that the odds of a C-section delivery at private hospitals for publicly insured women are higher than that for women covered by private insurance.

This pattern holds for the entire period of analysis, but is particularly high in recent years. By 2014, the C-section rate for births in private hospitals covered by public insurance rose as high as 77.2%. As dramatic as this figure seems, it is consistent with previous findings for the Chilean healthcare system.29

We evaluate whether the relationship between publicly insured deliveries at private hospitals and high C-section rates is driven by riskier patients seeking care at private institutions, for whom high C-section rates would be medically appropriate.30 We analyse hospital discharges related to maternal morbidity and mortality, and find no evidence that this is the case. Further, there is also no evidence from the average length of stay after delivery that suggests that outcomes are worse for mothers with public insurance delivering at private institutions.

Conclusions and implications

C-sections are resource intensive and a policy-relevant procedure. While an unprecedented increase in C-sections has heightened public awareness, measures to limit their use have not always been successful. This paper provides important insight relative to the interaction between public insurance and its private providers, and resultant C-section rates, at a time when private sector health providers play an increasingly relevant role in offering care around the world.12

We show that there is an association between high C-section rates and publicly insured women delivering at private institutions, and that it is this group that is driving the overall high and increasing rates of caesareans in Chile. Roughly, three out of four publicly insured women who opt to give birth in a private hospital will have a C-section, even though there is no evidence that these women would have been more likely to have a C-section out of medical necessity. Our findings indicate that there are potentially great health and financial benefits to be reaped from a more informed surveillance on the part of the public insurance system of its private providers’ C-section practices.