1. Predictors of epidural and spinal anesthesia use: A population-based analysis of Washington State, 2003-2004. Molly Altman, MN, CNM

2. Background Approximately 50% of laboring women use an epidural or spinal during labor for pain relief Approximately 50% of laboring women use an epidural or spinal during labor for pain relief Disparities in epidural use found across maternal age, parity, race/ethnicity, and insurance status Disparities in epidural use found across maternal age, parity, race/ethnicity, and insurance status Little data on disparities by hospital level, ownership, or teaching status. Little data on disparities by hospital level, ownership, or teaching status.

3. Research Aims The specific aim of the study was to: Examine the likelihood of epidural use when compared to perinatal level of hospital, ownership of hospital, and teaching status Examine the likelihood of epidural use when compared to perinatal level of hospital, ownership of hospital, and teaching status Secondary aims: Secondary aims: Subpopulations Subpopulations Low-risk women Low-risk women Spontaneous vaginal deliveries Spontaneous vaginal deliveries Low-risk women who had spontaneous vaginal deliveries Low-risk women who had spontaneous vaginal deliveries

4. Research Design & Methods Study design Study design Case control study using Washington State birth certificate data linked to the Comprehensive Hospital Abstract Reporting System (CHARS) Case control study using Washington State birth certificate data linked to the Comprehensive Hospital Abstract Reporting System (CHARS) Study population Study population All women who present in labor with a singleton, term, cephalic- presenting pregnancy, and had a live birth between 2003-2004 All women who present in labor with a singleton, term, cephalic- presenting pregnancy, and had a live birth between 2003-2004 Cases Cases Women who received an epidural or spinal in labor Women who received an epidural or spinal in labor Controls Controls Women who did not receive an epidural or spinal in labor Women who did not receive an epidural or spinal in labor

5. Research Design & Methods Exposures of interest Exposures of interest Level of perinatal unit of hospital Level of perinatal unit of hospital Primary, secondary, tertiary Primary, secondary, tertiary Ownership of hospital Ownership of hospital Public non-federal, private non-profit, private religious, private for-profit, military Public non-federal, private non-profit, private religious, private for-profit, military Teaching status of hospital Teaching status of hospital Yes, no Yes, no Outcome of interest Outcome of interest Epidural and/or spinal anesthesia use during labor Epidural and/or spinal anesthesia use during labor

6. Results Hospital Median rate of epidural use: 56%, 68 total hospitals included Distribution by hospital in Washington State

7. Characteristics of women who did and did not receive epidural analgesia during labor in Washington State, 2003. Variable Epidural% No epidural % Maternal age <182.83.0 18-2433.132.6 25-3451.650.9 35+12.513.5 Race/ethnicity of mother White78.665.2 Black3.84.2 Native American 2.12.6 Asian/Pacific Islander 8.79.5 Hispanic6.718.5 Parity150.235.6 232.028.9 3+20.932.5 Delivery payer Medicaid32.049.1 Private insurance 56.141.3 Government10.68.0 Other1.31.6

8. All deliveries Low-risk deliveries Spontaneous vaginal deliveries PredictoraOR 95% CI aOR aOR Level of perinatal unit Primary 1.0 (ref) Secondary1.9 1.3, 2.9 2.0 1.3, 3.1 2.0 1.3, 3.0 Tertiary2.4 1.5, 3.8 2.2 1.3, 3.9 2.3 1.4, 3.9 Ownership Public non-federal 1.0 (ref) Private non-profit 1.1 0.6, 1.9 1.2 0.6, 2.2 1.1 0.7, 1.9 Private Religious 1.1 0.7, 1.7 1.3 0.8, 2.1 1.2 0.8, 1.9 Private For-profit 1.1 0.4, 3.7 1.1 0.3, 4.2 1.1 0.3, 3.9 Military2.3 1.4, 3.9 NANANANA Note: aOR = adjusted odds ratio, CI = confidence interval, ref = reference category, NA = not available Associations between epidural use and predictors of interest, by subpopulation.

9. Conclusions There is significantly higher risk of epidural use in tertiary and secondary level obstetric units than primary level units. There is significantly higher risk of epidural use in tertiary and secondary level obstetric units than primary level units. This risk persists when low-risk women and women with spontaneous vaginal deliveries are examined. This risk persists when low-risk women and women with spontaneous vaginal deliveries are examined. More research is needed to determine if these differences in use are due to differential access, availability, or other hospital-level factors. More research is needed to determine if these differences in use are due to differential access, availability, or other hospital-level factors.

10. Thanks! Many thanks to: Many thanks to: Melissa Schiff, MD (chair) Melissa Schiff, MD (chair) Mona Lydon-Rochelle, CNM, PhD (committee) Mona Lydon-Rochelle, CNM, PhD (committee) Cathy Wasserman (Washington DOH) Cathy Wasserman (Washington DOH) Bill O’Brien (birth certificate guru) Bill O’Brien (birth certificate guru) This work was funded by a grant from the U.S. Department of Health and Human Services, Health Resources and Services Administration’s Maternal and Child Health Bureau (Title V, Social Security Act), grant #T76MC00011-21-00. This work was funded by a grant from the U.S. Department of Health and Human Services, Health Resources and Services Administration’s Maternal and Child Health Bureau (Title V, Social Security Act), grant #T76MC00011-21-00.