Use of neuraxial analgesia, or epidural, spinal, or combined spinal-epidural blockade, for women in labor varied substantially across the U.S., researchers found.
While there was substantial state-to-state variation in prevalence of neuraxial analgesia, only 5% of overall variation was explained by U.S. state — with the majority likely coming from unmeasured patient and hospital-level factors, reported Alexander J. Butwick, MBBS, of Stanford University School of Medicine in California, and colleagues, in JAMA Network Open.
They noted that women who receive neuraxial analgesia during labor have lower pain scores, higher satisfaction scores and are less likely to require additional pain relief than women receiving systemic opioid analgesia. Moreover, the American College of Obstetricians and Gynecologists (ACOG) recommends that “anesthesia services should be available to provide labor analgesia in all hospitals that offer maternal care.”
However, the authors cited “insufficient research” about whether similar geographic variations exist for neuraxial analgesia use as for abortion availability, labor induction, cesarean delivery, and perinatal outcomes.
They performed a retrospective cross-sectional analysis using birth certificate data from 2015. A total of 2,625,950 women who underwent labor were included in the sample.
About 30% of women were ages 25-29, followed by about 26% ages 30-34, and about 24% ages 20-24. More than 90% were either privately insured or insured with Medicaid, and about three-quarters of the final sample received neuraxial labor analgesia.
Older maternal age, non-white race and Hispanic ethnicity, no private insurance or no insurance, ≤12th grade education, and late or no prenatal care were all inversely associated with neuraxial analgesia, the authors said. However, women with a previous cesarean delivery were more likely to receive the procedure compared to women with no history of cesarean delivery, and women with no prior live birth were more likely than those who had live births before.
When examining use of neuraxial analgesia by state, Nevada had the highest adjusted neuraxial analgesia prevalence (80.1%, 95% CI 78.3%-81.7%) while Maine had the lowest adjusted prevalence (36.6%, 95% CI 33.2%-40.1%).
The adjusted median odds ratio was 1.5 (95% CI 1.4-1.6), which the authors explained as “if a woman moved to a state with a high probability of neuraxial labor analgesia, the odds of receiving neuraxial labor analgesia would increase by 50%.” But the intraclass correlation coefficient was 5.4% (95% CI 4.0%-7.9%) — which was described as “5.4% of the overall variation in neuraxial analgesia prevalence is explained by U.S. state.”
The authors said that their study could not explain why prevalence of neuraxial analgesia rates varied across states, speculating that in states with a low prevalence of use (such as Maine, Arkansas, Vermont, and Mississippi), a higher portion of the population lives in rural communities. Moreover, research has pointed to growing obstetric workforce shortages in rural hospitals, and the authors added that rural hospitals typically have lower obstetric volumes.
Another factor could be unmeasured confounders, such as lower health literacy, cultural and religious beliefs, and antenatal participation in childbirth education classes, they said. The authors also suggested that “knowledge and biases about the effects of neuraxial analgesia among patients and healthcare professionals may vary by state.”
“With ACOG guidelines stating that anesthesia services should be available to provide labor analgesia in all hospitals that provide maternal care, efforts should be made to better understand the main reasons for the variation and whether this variation influences maternal or perinatal outcomes,” they concluded.
One potential limitation to the data is that despite a high sensitivity, “specificity of neuraxial analgesia on birth certificates has not been previously reported.”
This study was supported by the Stanford University School of Medicine.
Butwick disclosed support from Instrumentation Laboratory and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.
One co-author disclosed support from the National Institute on Drug Abuse.