Isaac Lowenwirt, M.D., Peter Silverberg, M.D., Patricia Pierre, BSN, Julia Tai, MA, Daniel Skupski, M.D.
Introduction: Lumbar epidural analgesia is considered to be the most effective method of intrapartum pain relief with the least depressant effects on the fetus compared with all other pharmacological methods. Despite the superiority and widespread availability of epidural analgesia, ethnic disparities in the provision of epidural analgesia exist. A recent retrospective study of 83,000 women using a New York State perinatal database found that African American and Hispanic women were significantly less likely to receive epidural analgesia during labor than white women, even after accounting for differences in insurance coverage (2). Patient preference, provider bias, and treatment by different physicians were not controlled for in their study making it difficult to determine whether there are true ethnic differences in epidural utilization.We have perceived a markedly different experience at our institution in regards to the acceptance and provision of labor epidural analgesia. The aims of this current study are to investigate whether there are ethnic differences in both epidural utilization and in the amount of medication used to achieve analgesia.
Methods: This was a prospective cohort study of all women with singleton fetuses in the cephalic presentation delivering at a large tertiary center in the most culturally diverse county in the USA(Queens,NY). Institutional review board approval was obtained for this prospective observational study. The study included 800 consecutive parturients in labor between July 1, 2007 and Nov 30, 2007. Exclusion criteria were planned cesarean delivery, malpresentation and multifetal gestation. Patients in active labor were given a choice for labor analgesia between parenteral fentanyl, patient controlled epidural analgesia or no medication. The nursing staff completed a data sheet for each patient containing maternal demographics and obstetrical data( Table 1). Severity of pain, efficacy of analgesia and patient satisfaction scores were measured by visual analog scale (VAS) from (1-10). Amount of bupivacaine was recorded as total dose used in milligrams and milligrams per hour for those patients who received PCEA. Statistical analysis was performed using Chi-Square test for categorical data and the Kruskal-Wallis test for continuous data to screen if any variables potentially associated with either ethnicity or epidural utilization.Multiple logistic regression was performed to determine variables that predicted patients’ choice of analgesia. We chose Chinese/Korean group as the comparison group as opposed to Caucasian since they represented the dominant ethnic group at our Instituion (42.4%). We used the ethnic distribution at our Institution (see Table 1) as the basis for a sample size calculation and considered 5% difference in epidural utilization between any ethnic groups to be clinically significant. The results showed that 800 patients were necessary to show significance with alpha 5% and beta 90%.
Results: The study sample consisted of 800 patients. Ethnic diversity was seen with 42.4% of the patients Chinese-Korean, 18.8% of the patients Hispanic, 12.9% of the patients Caucasian, 9.8% of the patients African American, 8.4% of the patients Indian/Pakistani, and 7.7% others. Overall 81.9% of the patients selected epidural analgesia. There were no significant differences among the group that selected epidural compared to those who declined in regards to education and insurance (Table 1). Table 1 summarizes the result of the univariate analysis between the utiliztion of epidural. Univariate analysis according to ethnicity was measured. Age,BMI, birth weight and duration of of labor analgesia were significantly different among ethnic groups.. Chinese/Korean patients tended to be older (mean age ± SD: 29.6±4.6) and Hispanic patients were younger (27.0±5.7). BMI was highest among African Americans(31.1±6.5) and lowest in Chinese/Koreans (26.9±3.7). The Caucasian and Hispanic populations had infants that weighed the most (3.3kg±0.4, 3.4±0.6, respectively) and Indian infants weighed the least (3.2±0.4). Chinese/Korean patients had the shortest duration of analgesia (141min±104.7) and the African/American and Hispanic populations had the longest duration of analgesia (185.4min±128.3, 174.3±121.2, respectively). There were ethnic differences in epidural consumption as indicated by mg/hr bupivacaine used. Hispanic patients used the most at 7.3 mg/hr and Chinese/Korean patients used the least at 5.5 mg/hr (p< 0.0001). Operative delivery rates between the ethnic groups were not different. Pain scores and patient satisfaction of the ethnic groups as measured by visual analog score (VAS1-10) were done. The baseline pain score of those patients requesting epidural was much higher and did not vary among ethnic groups than those not requesting epidural. There were no ethnic differences in the initial VAS score or in the VAS score after epidural placement.Patients who received epidural analgesia had higher baseline VAS score (8.8±1.3) than patients not receiving epidural (3.7±1.5, p< 0.0001). There was a high level of patient satisfaction among all ethnic groups which was not significantly different.Parity and and ethnicity predicted epidural use by logistic regression. Nulliparas chose epidural more than multiparas (OR=4.0, 95% CI 2.6-6.2, p< 0.0001). Hispanics chose epidural more than Chinese/Koreans (OR=2.07,95% CI, CI 1.1-4.0,p=0.03).
Conclusion: In this study we found that when equal access to epidural analgesia is available, all ethnicities choose epidural analgesia in approximately the same proportions.Socioeconomic factors and level of education did not interfere with the high demand rate of epidural analgesia.This is in contrast to previous reports showing significant differences depending on ethnicity, and suggests that education about and availability of, epidural analgesia are important determinants of patient choice.Our results are in keeping with the goals stated in Healthy People 2010 in eliminating racial disparities in pain management(3) . Hispanic patients require further study to determine whether dose requirements and epidural utilization in mutiparous patients are actually different.
1.GlanceLG,WisslerR,GlantzC,OslerTM,MukamelDB,DickAW: Racial differences in the use of epidural analgesia for labor.Anesthesiology 2007;106:19-25
2.US Department of Health and human services; Healthy People 2010:Understanding and Improving Health. WASHINGTON ,D.C.., Department of Health and Human Services,Government Printing Office,2000
TABLE 1 - Obstetric and Demographic Characteristics of Subjects Selecting and Declining Epidural Analgesia
# / Total % P-Value
Nulliparous 314 / 342 91.8% * <0.0001
Multiparous 339 / 455 74.5%
Grade School 42 / 57 73.7% 0.1182
High School 229 / 270 84.8%
College or Higher 382 / 470 81.3%
Private 437 / 536 81.5% 0.6722
Service 216 / 261 82.8%
Induction/Augmentation 242/258 93.8% * <0.0001
Spontaneous 411/539 76.3%
Yes 60 / 73 82.2% 0.9518
No 593 / 724 81.9%
Yes 243 / 281 86.5% * 0.0139
No 410 / 516 79.5%
NSVD 519 / 658 78.9% * <0.0001
Operate 134 / 138 97.1%
African American 66 / 78 84.6% 0.0718
Caucasian 83 / 103 80.6%
Chinese / Korean 268 / 338 79.3%
Hispanic 133 / 150 88.7%
Indian / Pakistani 50 / 67 74.6%
Other 53 / 61 86.9%
* = significant (<0.05)