J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website http://www.jocmr.org

Original Article

Volume 4, Number 2, April 2012, pages 119-126

Risk Factors Associated With Epidural Use

**Table 1.** Characteristics of Epidural Users and non, Users who Gave Birth Vaginally to Singletons in Washington State, 2009
		Epidural users (n = 21,705)	Epidural non-user (n = 21,705)
^aPercentages may not add to 100 due to rounding. Numbers may not add to total due to missing data.
	Maternal Variables
	Variable	Mean (SD)	Mean (SD)

	Maternal Age (years)	27.10 (5.87)	27.94 (5.98)
	Parity	0.92 (1.24)	1.33 (1.46)
	Education (years)	13.28 (2.63)	12.65 (3.18)

	Status	n (%)^a	n (%)^a

Marital Status	Married	14,034 (65.10)	13,981 (65.10)
Unmarried	7,523 (34.90)	7,496 (34.90)
Insurance Provider	Government	10,458 (48.92)	11,997 (56.18)
Uninsured	147 (0.69)	206 (0.97)
Private	10,773 (50.39)	9,088 (42.85)
Induction of Labor	Spontaneous	15,164 (70.22)	18,174 (84.22)
Induced	6,430 (29.78)	3,404 (15.78)
Smoking During Pregnancy	Did Not Smoke	18,955 (88.60)	19,900 (92.70)
Smoked	2,439 (11.40)	1,567 (7.30)
Race	Non-Hispanic White	16,186 (75.72)	13,320 (62.58)
Non-Hispanic Black	1,030 (4.82)	1,029 (4.83)
Hispanic	1,713 (8.01)	4,091 (19.22)
Asian	1,844 (8.63)	2,117 (9.95)
Other	603 (2.82)	728 (3.42)

	Hospital Variables
	Location	n (%)^a	n (%)^a

Perinatal Unit Tier	Primary	4,798 (23.85)	2,879 (15.32)
Secondary or Tertiary	15,322 (76.15)	15,912 (84.68)
Hospital Location	Urban	16,324 (83.58)	16,502 (91.91)
Rural	3,208 (16.42)	1,453 (8.09)
Hospital Ownership	Not for Profit	13,534 (68.09)	13,376 (68.83)
District	5,164 (25.98)	3,671 (18.89)
For Profit	319 (1.60)	425 (2.19)
State	514 (2.59)	511 (2.49)
Military	347 (1.75)	1,478 (7.61)

Table 1. Characteristics of Epidural Users and non, Users who Gave Birth Vaginally to Singletons in Washington State, 2009

Epidural users
(n = 21,705)

Epidural non-user
(n = 21,705)

^aPercentages may not add to 100 due to rounding. Numbers may not add to total due to missing data.

Maternal Variables

Variable

Mean (SD)

Maternal Age (years)

27.10 (5.87)

27.94 (5.98)

Parity

0.92 (1.24)

1.33 (1.46)

Education (years)

13.28 (2.63)

12.65 (3.18)

Status

n (%)^a

Marital Status

Married

14,034 (65.10)

13,981 (65.10)

Unmarried

7,523 (34.90)

7,496 (34.90)

Insurance Provider

Government

10,458 (48.92)

11,997 (56.18)

Uninsured

147 (0.69)

206 (0.97)

Private

10,773 (50.39)

9,088 (42.85)

Induction of Labor

Spontaneous

15,164 (70.22)

18,174 (84.22)

Induced

6,430 (29.78)

3,404 (15.78)

Smoking During Pregnancy

Did Not Smoke

18,955 (88.60)

19,900 (92.70)

Smoked

2,439 (11.40)

1,567 (7.30)

Race

Non-Hispanic White

16,186 (75.72)

13,320 (62.58)

Non-Hispanic Black

1,030 (4.82)

1,029 (4.83)

Hispanic

1,713 (8.01)

4,091 (19.22)

Asian

1,844 (8.63)

2,117 (9.95)

Other

603 (2.82)

728 (3.42)

Hospital Variables

Location

n (%)^a

Perinatal Unit Tier

Primary

4,798 (23.85)

2,879 (15.32)

Secondary or Tertiary

15,322 (76.15)

15,912 (84.68)

Hospital Location

Urban

16,324 (83.58)

16,502 (91.91)

Rural

3,208 (16.42)

1,453 (8.09)

Hospital Ownership

Not for Profit

13,534 (68.09)

13,376 (68.83)

District

5,164 (25.98)

3,671 (18.89)

For Profit

319 (1.60)

425 (2.19)

State

514 (2.59)

511 (2.49)

Military

347 (1.75)

1,478 (7.61)

**Table 2.** Odds Ratios of Associations Between Intrapartum Epidural Analgesia Use and Individual Variables in Washington State, 2009
Maternal Factors	Adjusted OR (95% CI)^a
^aAdjusted for maternal age, insurance, and hospital ownership. Robust multivariate logistic regression was used to determine odds ratios and confidence intervals.
Induced Labor
Induced	Referent
Spontaneous	2.16 (2.06, 2.27)
Smoking during pregnancy
Did Not Smoke	Referent
Smoked	1.71 (1.59, 1.84)
Race
Non-Hispanic White	Referent
Non-Hispanic Black	0.86 (0.79, 0.95)
Hispanic	0.37 (0.35, 0.40)
Asian	0.79 (0.73, 0.85)
Education
High school degree or higher education	Referent
No high school degree	0.55 (0.52, 0.58)

Table 2. Odds Ratios of Associations Between Intrapartum Epidural Analgesia Use and Individual Variables in Washington State, 2009

Maternal Factors

Adjusted OR
(95% CI)^a

^aAdjusted for maternal age, insurance, and hospital ownership. Robust multivariate logistic regression was used to determine odds ratios and confidence intervals.

Induced Labor

Induced

Referent

Spontaneous

2.16 (2.06, 2.27)

Smoking during pregnancy

Did Not Smoke

Referent

Smoked

1.71 (1.59, 1.84)

Race

Non-Hispanic White

Referent

Non-Hispanic Black

0.86 (0.79, 0.95)

Hispanic

0.37 (0.35, 0.40)

Asian

0.79 (0.73, 0.85)

Education

High school degree or higher education

Referent

No high school degree

0.55 (0.52, 0.58)

**Table 3.** Odds of Epidural Use According to Foreign Birth Status Stratified by Maternal Race in Washington State in 2009
Foreign Birth Stratum	Adjusted OR (95% CI)^a
^aAdjusted for maternal age, insurance, and hospital ownership. Robust multivariate logistic regression was used to determine odds ratios and confidence intervals.
All
US-Born	Referent
Foreign-born	0.51 (0.49, 0.53)
Non-Hispanic White
US-Born	Referent
Foreign-born	0.52 (0.49, 0.56)
Non-Hispanic Black
US-Born	Referent
Foreign-born	0.35 (0.29, 0.43)
Hispanic
US-Born	Referent
Foreign-born	0.68 (0.59, 0.78)
Asian
US-Born	Referent
Foreign-born	0.96 (0.82, 1.12)

Table 3. Odds of Epidural Use According to Foreign Birth Status Stratified by Maternal Race in Washington State in 2009

Foreign Birth Stratum

Adjusted OR (95% CI)^a

^aAdjusted for maternal age, insurance, and hospital ownership. Robust multivariate logistic regression was used to determine odds ratios and confidence intervals.

All

US-Born

Referent

Foreign-born

0.51 (0.49, 0.53)

Non-Hispanic White

US-Born

Referent

Foreign-born

0.52 (0.49, 0.56)

Non-Hispanic Black

US-Born

Referent

Foreign-born

0.35 (0.29, 0.43)

Hispanic

US-Born

Referent

Foreign-born

0.68 (0.59, 0.78)

Asian

US-Born

Referent

Foreign-born

0.96 (0.82, 1.12)

**Table 4.** Associations of Health Care Related Factors With Intrapartum Epidural Analgesia Use in Washington State in 2009
Health Care Related Factors	Adjusted OR (95% CI)^a
^aAdjusted for maternal age, insurance, induction, race and education. Robust multivariate logistic regression was used to determine odds ratios and confidence intervals.
Perinatal Unit Tier
Primary	Referent
Secondary or Tertiary	1.61 (1.52, 1.70)
Location
Urban	Referent
Rural	0.48 (0.44, 0.51)
Ownership
Not for Profit	Referent
District	0.78 (0.74, 0.82)
For Profit	1.37 (1.18, 1.61)
State	1.08 (0.94, 1.23)
Military	5.29 (4.67, 6.00)

Table 4. Associations of Health Care Related Factors With Intrapartum Epidural Analgesia Use in Washington State in 2009

Health Care Related Factors

Adjusted OR
(95% CI)^a

^aAdjusted for maternal age, insurance, induction, race and education. Robust multivariate logistic regression was used to determine odds ratios and confidence intervals.

Perinatal Unit Tier

Primary

Referent

Secondary or Tertiary

1.61 (1.52, 1.70)

Location

Urban

Referent

Rural

0.48 (0.44, 0.51)

Ownership

Not for Profit

Referent

District

0.78 (0.74, 0.82)

For Profit

1.37 (1.18, 1.61)

State

1.08 (0.94, 1.23)

Military

5.29 (4.67, 6.00)