Differences in Institutional Cesarean Delivery Rates: The Role of Pain Management

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Original Research

Differences in Institutional Cesarean Delivery Rates: The Role of Pain Management

J Fam Pract. 2001 March;50(3):217-225

References

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Phase II

Our sample consisted of 24 laboring women at Burnaby and 26 laboring women at BC Women’s. The groups were comparable in mean age, marital status, employment, and parity. There were more white women: 18 (75%) in the Burnaby group compared with 11 (42.3%) in the BC Women’s group.

Almost all the women were accompanied by support persons, 24 (100%) at Burnaby and 25 (96.2%) at BC Women’s. The majority at Burnaby had been to childbirth education classes (18 [78.3%] vs 14 [58.3%] at BC Women’s).

It was not possible to observe all the women throughout the entire length of labor. Given this reality and the fact that length of labor differed between women, observations related to management of labor were expressed as rates (ie, the number of minutes spent in bed divided by the total observation time in hours). Women in the 2 hospitals spent similar amounts of time in bed and in the shower. Women at Burnaby spent significantly more time walking, 12 minutes per hour compared with 4.7 minutes per hour at BC Women’s (P=.01, Table 4). There was no difference between the 2 hospital groups in the amount of physical contact with the laboring woman and her nurse or support person. At BC Women’s, women were more often accompanied by a nurse, physician, medical student, or resident and less often left alone than at Burnaby. Women at BC Women’s were exposed to greater numbers of different caregivers.

There were no differences between the groups in the number of couples who expressed specific expectations of labor Table 5. Ten women in Burnaby and 8 in BC Women’s were observed to ask for help with pain management, and responses to these requests included general encouragement or specific verbal advice as to what method they should use. Women were more frequently offered epidural analgesia at BC Women’s; there were no differences in rates of offers for other pain management options. This question related to a preemptive discussion about pain management. In terms of the pain management that actually took place, there was a significant difference in the number of doses of narcotic, in that no women at BC Women’s received narcotics. There was a trend toward more exposure to Entonox and epidural at BC Women’s, although these differences were not significant.

Discussion

Institutional differences in cesarean birth rates have previously been associated with differences in maternity care practices.⁵ The time during labor (state of cervical dilatation) at which women are admitted to the hospital has been associated with cesarean delivery rate.⁶

Age as a risk factor for cesarean delivery has also been well documented. The influence of age appears to be important independent of risk and remains important even among women without risk factors.^7-9 The reason for this is unknown but may point to an association with physician bias or age-related biological factors in the labor process that remain unmeasured.^10,11

The need for oxytocin augmentation has been associated with cesarean delivery.¹² Randomized controlled trials, however, have not demonstrated an association of early use of oxytocin augmentation with cesarean delivery reduction.¹³ Augmentation did not contribute significantly to the model examining differences in cesarean delivery between hospitals when an epidural was included.

A meta-analysis by Halpern and colleagues¹⁴ evaluated the association of epidural analgesia and cesarean delivery. In that report there was no increase in risk of cesarean delivery associated with use of epidural versus narcotic analgesia (OR=1.28; 95% CI, 0.55-2.93 for nulliparous women; OR=0.83; 95% CI, 0.22-3.15 for multiparous women). Findings from the intention-to-treat analysis that could not overcome the limitation of high rates of crossover or noncompliance among some of the trials^15-17 are in contrast with a protocol-compliant analysis in some of the studies that did show an effect of epidural on cesarean delivery rates.¹⁵ Although the protocol-compliant analysis provides important information, it does not necessarily indicate that epidural analgesia is the cause of higher cesarean rates. Subjects having more difficult labors may be more likely to cross over to epidural analgesia from the narcotic arm of the study, increasing the potential need for cesarean delivery in the epidural arm. In the meta-analysis the cesarean delivery rate among women receiving epidurals was 8.2%,¹⁴ much lower than at BC Women’s and more in line with those at Burnaby. The results, therefore, may not be generalizable to BC Women’s, at which high cesarean delivery rates would indicate greater opportunity for changes in intrapartum management, including use of epidural analgesia, to influence cesarean delivery rate.

An important aspect of our work addressed in phase II, our observation study, considered characteristics of women choosing delivery at either hospital that might also influence their choice to use an epidural. Although there were differences in ethnic background between the 2 study groups, these differences did not explain the difference in cesarean delivery rate between the 2 hospitals in our larger study. Although the differences were not statistically significant, more women at Burnaby appeared to have attended prenatal classes. The literature to date has not demonstrated an effect of prenatal education on cesarean delivery.¹⁸