C-section rates as a marker for obstetric care quality

by Michael Smith

When cesarean section rates are lower than expected, adverse maternal or neonatal outcomes are higher, researchers said.

But the converse isn’t true — higher-than-expected C-section rates aren’t associated with a protective effect, according to Sindhu Srinivas, MD, of the University of Pennsylvania, and colleagues.

The finding comes from an attempt to see if the risk-adjusted C-section rate can be used as a marker for the quality of obstetric care, Srinivas and colleagues wrote in the May issue of Obstetrics & Gynecology.

The measure has been proposed previously, but has been criticized for including all deliveries — including those where it is medically necessary — and because the overall rate of C-sections had been rising.

Nevertheless, Srinivas and colleagues wrote, the risk-adjusted C-section rate is an attractive measure — it has “face validity, easy measurability, and construct validity.”

To evaluate the measure in the current climate, the researchers constructed a population-based cohort of 845,651 patients from 401 hospitals in California and Pennsylvania. They excluded premature births and those in which C-sections were standard of care (such as for malpresentation and cord prolapse).

As well as analyzing the overall cohort, the researchers looked separately at the 274,371 primiparous patients with full-term singleton pregnancies.

For both groups, they linked birth certificate and hospital admission records to estimate the correlation between risk-adjusted cesarean delivery and a composite of adverse maternal outcomes, adverse neonatal outcomes, and four obstetric patient safety indicators from the Agency for Healthcare Research and Quality (AHRQ).

The composite maternal outcome included such events as wound infection and postdelivery hemorrhage, and the composite neonatal outcome included such things as death and birth injury. The AHRQ indicators included such things as birth trauma and injury with cesarean delivery.

The researchers used logistic regression to calculate an expected rate of C-section for each hospital and compared that with the observed rate.

In both cohorts, there was a negative correlation between the C-section rate and each of the outcomes, which was significant except for one — AHRQ patient safety indicator 19 (injury with non-instrumented vaginal delivery).

Comparing C-section and adverse events rates showed that, in the general cohort:

* 59.8% of the 107 hospitals with lower-than-expected risk-adjusted C-section rates had a higher-than-expected rate of at least one of the six adverse outcomes.
* Only 19.6% of the 102 hospitals with higher-than-expected risk-adjusted C-section rates had a higher-than-expected rate of any of the six adverse outcomes.
* The comparable figure was 36.1% for the hospitals with the as-expected risk-adjusted C-section rates, which was statistically similar to the higher-than-expected group.

The pattern was similar in the primiparous subcohort, Srinivas and colleagues found.

“We speculate that, in some instances, patients benefit from having (cesarean) deliveries,” the researchers said, so that hospitals whose medical staff “do not act fast enough” to perform them may have a higher rate of adverse outcomes.

On the other hand, performing too many C-sections wasn’t associated with improved outcomes, they noted, adding that the finding “should not suggest” that the practice is desirable.

Instead, they said, “it likely reflects an overuse of medical care and the performance of unnecessary procedures.”

Srinivas and colleagues cautioned that they did not use primary chart abstraction to identify comorbidities and complications, opening the door to a misclassification bias.

They noted that it is also possible that some unobserved factors confounded the results. The observation does not prove a causal effect, they added.

Michael Smith is a MedPage Today North American Correspondent.

Originally published in MedPage Today. Visit MedPageToday.com for more obstetrics news.

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  • http://nostrums.blogspot.com Doc D

    At the risk of being thought a simpleton, I had a tough time developing any take-away from this study.

    There’s nothing that links up birth certificate and admission record data with the quality of clinical decision-making.

    This and the other limitations that the authors recognize leave us with the narrow conclusion that…complications occur.

  • rezmed09

    C-section rates probably are more dependent on local prevailing rates of lawsuits or recent lawsuits within a practice. Just a guess.

  • http://thederangedhousewifeonline.blogspot.com/ The Deranged Housewife

    I’m with Doc D: I’m not sure what this article is really trying to say here.

    I don’t agree that a lower-than-expected c-section rate can always be associated with adverse outcomes – that is jumping to conclusions. In most cases, unless absolutely needed, interventions can increase the rate of risks (although not always leading to a c-section) for both the mom and the baby. I also agree with Michele – have we looked at things like secondary infertility as a result of multiple c-sections, chronic pelvic pain and other disorders or is it just too hard to “prove” that those problems are a direct result of your multiple cesareans a decade or two ago?

  • Brige

    I agree with Doc D… kind of a convoluted article… I am a firm believer that if the normal pysiological process of birth isn’t allowed to happen, that you in turn end up in numerous interventions that can lead to “unneccessarians.” Statistically as a country we have horrid maternal and infant mortality rates, and we’re paying more in the process per mother.
    There was an interesting article from Chinese Dr’s who said they would not make any money if they didn’t do c-sections… I also wonder about the ease for drs to do C/s vs waiting 20-30 hours to delivery a baby vaginally… I think the way we treat women in labor (keeping women strapped in beds, not allowing them to eat, constant efm, rushing into using pit. if things aren’t progressing on Schedule, forcing women to purple push not to mention the limitation of birthing positions to something that is only beneficial to Drs ) does not precipitate a low c/s rate and high success rate for vaginal deliveries with out complications. The model of care has to change from protecting Drs and hospital bank accounts to doing what is best for mom and baby, and allowing them to actively participate in the decision making regarding their individual birth. when that happens I think Drs will get sued less, women and babies will die less and we’ll end up spending less…
    Pardon the long rant…

  • michele

    So much time is being given to these studies that compare c-sections to vaginal birth, to VBAC, or “Comparing C-section and adverse events rates” etc. etc…

    But we have yet to see the consequences of LONG TERM over-use of cesarean delivery. Many of these women are getting multiple cesareans –major abdominal surgery–we have yet to see the outcomes on the health of these women in the future.

  • http://jimenezrachel@comcast.net Rachel

    michele, you’re right. We know that with each additional cesarean a woman receives, her risk of hysterectomy, adhesions, placental abnormalities like accreta increase. So while there isn’t much talk about it, we know that those long term risks are there and need to be accounted for.

  • http://www.Birthrisk.com Gustavo San Roman, MD

    I am an obstetrician with over twenty years of experience who is trying to decrease the number of cesarean deliveries. I believe that you will not be able to reduce the number of unnecessary cesarean deliveries until you take the time to better understand the statistics. Once you better understand the statistics you will realize that what we need is a cesarean birth measure not a cesarean delivery rate. A cesarean birth measure corrects a cesarean delivery rate using the main risk factors that increase a woman’s chance of having a cesarean delivery. With this correction we can find the labor management strategies that will result in the fewest number of cesarean deliveries. The method used to create the risk adjusted cesarean delivery rates in this article is a severely flawed. You can find information on the pitfalls of the current way that we report cesarean delivery rates as well as the answer to why is the cesarean rate increasing on my website http://www.Birthrisk.com.