Predictors of epidural Predictors of epidural and spinal anesthesia and spinal anesthesia

use: A population-based use: A population-based analysis of analysis of

Washington State, 2003-Washington State, 2003-2004.2004.

Molly Altman, MN, CNMMolly Altman, MN, CNM

BackgroundBackground

Approximately 50% of laboring Approximately 50% of laboring women use an epidural or spinal women use an epidural or spinal during labor for pain reliefduring labor for pain relief

Disparities in epidural use found Disparities in epidural use found across maternal age, parity, across maternal age, parity, race/ethnicity, and insurance statusrace/ethnicity, and insurance status

Little data on disparities by hospital Little data on disparities by hospital level, ownership, or teaching status.level, ownership, or teaching status.

Research AimsResearch AimsThe specific aim of the study was to:The specific aim of the study was to: Examine the likelihood of epidural use Examine the likelihood of epidural use

when compared to perinatal level of when compared to perinatal level of hospital, ownership of hospital, and hospital, ownership of hospital, and teaching statusteaching status

Secondary aims:Secondary aims: SubpopulationsSubpopulations

Low-risk womenLow-risk women Spontaneous vaginal deliveriesSpontaneous vaginal deliveries Low-risk women who had spontaneous vaginal Low-risk women who had spontaneous vaginal

deliveriesdeliveries

Research Design & Research Design & MethodsMethods

Study designStudy design Case control study using Washington State birth Case control study using Washington State birth

certificate data linked to the Comprehensive Hospital certificate data linked to the Comprehensive Hospital Abstract Reporting System (CHARS)Abstract Reporting System (CHARS)

Study populationStudy population All women who present in labor with a singleton, All women who present in labor with a singleton,

term, cephalic-presenting pregnancy, and had a live term, cephalic-presenting pregnancy, and had a live birth between 2003-2004birth between 2003-2004

CasesCases Women who received an epidural or spinal in laborWomen who received an epidural or spinal in labor

ControlsControls Women who did not receive an epidural or spinal in Women who did not receive an epidural or spinal in

laborlabor

Research Design & Research Design & MethodsMethods

Exposures of interestExposures of interest Level of perinatal unit of hospitalLevel of perinatal unit of hospital

Primary, secondary, tertiaryPrimary, secondary, tertiary Ownership of hospitalOwnership of hospital

Public non-federal, private non-profit, private Public non-federal, private non-profit, private religious, private for-profit, militaryreligious, private for-profit, military

Teaching status of hospitalTeaching status of hospital Yes, noYes, no

Outcome of interestOutcome of interest Epidural and/or spinal anesthesia use during Epidural and/or spinal anesthesia use during

laborlabor

ResultsResults

0.2

.4.6

.8F

requ

ency

of

epid

ural

Hospital

Median rate of epidural use: 56%, 68 total hospitals included

Distribution by hospital in Washington State

Characteristics of women who did and did not receive Characteristics of women who did and did not receive epidural analgesia during labor in Washington State, 2003.epidural analgesia during labor in Washington State, 2003.

VariableVariableEpiduralEpidural

%%No epiduralNo epidural

%%

Maternal ageMaternal age <18<18 2.8 2.8 3.03.0

18-2418-24 33.1 33.1 32.632.6

25-3425-34 51.651.6 50.950.9

35+35+ 12.512.5 13.513.5

Race/ethnicity of Race/ethnicity of mothermother

WhiteWhite 78.678.6 65.265.2

BlackBlack 3.83.8 4.24.2

Native AmericanNative American 2.12.1 2.62.6

Asian/Pacific Asian/Pacific IslanderIslander

8.78.7 9.59.5

HispanicHispanic 6.76.7 18.518.5

ParityParity 11 50.250.2 35.635.6

22 32.032.0 28.928.9

3+3+ 20.920.9 32.532.5

Delivery payerDelivery payer MedicaidMedicaid 32.032.0 49.149.1

Private insurancePrivate insurance 56.156.1 41.341.3

GovernmentGovernment 10.610.6 8.08.0

OtherOther 1.31.3 1.61.6

All deliveriesAll deliveries Low-risk Low-risk deliveriesdeliveries

Spontaneous Spontaneous vaginal vaginal deliveriesdeliveries

PredictorPredictor aORaOR 95% CI95% CI aORaOR 95% 95% CICI

aORaOR 95% 95% CICI

Level of Level of perinatal unitperinatal unit

PrimaryPrimary 1.0 1.0 (ref)(ref)

1.0 1.0 (ref)(ref)

1.0 1.0 (ref)(ref)

SecondarySecondary 1.91.9 1.3, 2.91.3, 2.9 2.02.0 1.3, 1.3, 3.13.1

2.02.0 1.3, 1.3, 3.03.0

TertiaryTertiary 2.42.4 1.5, 3.81.5, 3.8 2.22.2 1.3, 1.3, 3.93.9

2.32.3 1.4, 1.4, 3.93.9

OwnershipOwnership Public non-Public non-federalfederal

1.0 1.0 (ref)(ref)

1.0 1.0 (ref)(ref)

1.0 1.0 (ref)(ref)

Private non-Private non-profitprofit

1.11.1 0.6, 1.90.6, 1.9 1.21.2 0.6, 0.6, 2.22.2

1.11.1 0.7, 0.7, 1.91.9

Private Private ReligiousReligious

1.11.1 0.7, 1.70.7, 1.7 1.31.3 0.8, 0.8, 2.12.1

1.21.2 0.8, 0.8, 1.91.9

Private For-Private For-profitprofit

1.11.1 0.4, 3.70.4, 3.7 1.11.1 0.3, 0.3, 4.24.2

1.11.1 0.3, 0.3, 3.93.9

MilitaryMilitary 2.32.3 1.4, 3.91.4, 3.9 NANA NANA NANA NANA

Note: aOR = adjusted odds ratio, CI = confidence interval, ref = reference Note: aOR = adjusted odds ratio, CI = confidence interval, ref = reference category, NA = not availablecategory, NA = not available

Associations between epidural use and predictors of interest, by subpopulation.

ConclusionsConclusions

There is significantly higher risk of epidural There is significantly higher risk of epidural use in tertiary and secondary level obstetric use in tertiary and secondary level obstetric units than primary level units.units than primary level units. This risk persists when low-risk women and This risk persists when low-risk women and

women with spontaneous vaginal deliveries are women with spontaneous vaginal deliveries are examined.examined.

More research is needed to determine if More research is needed to determine if these differences in use are due to these differences in use are due to differential access, availability, or other differential access, availability, or other hospital-level factors. hospital-level factors.

Thanks!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. This work was funded by a grant from the U.S. Department of Health and Human Services, Department of Health and Human Services, Health Resources and Services Administration’s Health Resources and Services Administration’s Maternal and Child Health Bureau (Title V, Maternal and Child Health Bureau (Title V, Social Security Act), grant #T76MC00011-21-00. Social Security Act), grant #T76MC00011-21-00.