Elizabeth Lawlor, Advanced Epidemiologist

Healthy Kansans living in safe and sustainable environments.

Maternal, Infant, and Hospital Level Factors Associated with Newborn

Hepatitis B Vaccination – Kansas, 2009

Elizabeth Lawlor, Advanced Epidemiologist

BACKGROUND

Hepatitis B• Caused by hepatitis B virus (HBV)• ~ 4.4 million in US living with chronic HBV• Often asymptomatic• Transmission

• Sexual• Parenteral• Perinatal

• Perinatal: infection of infant after birth • Risk of perinatal HBV infection among infants born to

HBV+ mothers ranges from 10%-85%

Chronic HBV

• Major cause of: • Cirrhosis of the liver• Primary hepatocellular carcinoma

• Development of chronic HBV is age dependent • Primary develops into chronic infection

• 5% of healthy older children and adults • 30% of children <5 years old• 90% of infants

Chronic HBV

• ~ 25% of infected infants will develop: • Chronic liver disease• Cirrhosis• Hepatocellular carcinoma

• ~ 25% of infants with complications will die as young adults

Outcome of HBV Infection by Age at Infection

Symptomatic Infection

Chronic Infection

Chr

onic

Infe

ctio

n (%

)

Sym

ptom

atic

Infe

ctio

n (%

)

Birth 1-6 months 7-12 months 1-4 years Older Childrenand Adults

0

20

40

60

80

100100

80

60

40

20

0

Ward, John and Prevention, Centers for Disease Control and. Hapatitis A Through E: An Overview. University of Alabama at Birmingham. [Online] 2007. www.microbio.uab.edu/medmicro/lectures/ward.ppt.

Preventing Perinatal Infections• Hepatitis B immune globulin (HBIG) and HBV vaccine

birth dose administered at birth• ≥ 95% effective at preventing infection for infants born to HBV+

moms• HBV vaccine (without HBIG) is 70% - 95% at preventing

transmission from mother to child• Several case reports of infants contracting HBV because of

no chemoprophylaxis at birth• HBV birth dose recommended for all medically stable

infants > 2,000 grams regardless of maternal status

Centers for Disease Control and Prevention. Recommendations of the Advisory Committee on Immunization Practices (ACIP). A Comprehensive Immunization Strategy to Eliminate Transmission of Hepatitis B Virus Infection in the United States: Immunization of Infants, Children, and Adolescents. MMWR. 2005, Vol. 54, RR16. Centers for Disease Control and Prevention. Recommendations of the Immunization Practices Advisory Committee Prevention of Perinatal Transmission of Hepatitis B Virus: Prenatal Screening of all Pregnant Women for Hepatitis B Surface Antigen. MMWR. 1988, Vol. 37, 22.

Universal Birth Dose Policy

• Provided by Kansas Department of Health and Environment (KDHE) to hospitals enrolled in Vaccines For Children program

• Hepatitis B vaccine is offered, at no cost, for all infants regardless of insurance status

Objective

• To determine what factors are associated with hepatitis B birth dose receipt at Kansas hospitals

METHODS

Study

• Retrospective cohort study• Data sources

• Hospital policy survey• 2009 birth registry data

Hospital Policy Survey

• Survey was sent to all birthing hospitals’ labor and delivery units

• Assessed 2009 policies• Policies to prevent perinatal infections (hepatitis B, HIV, and

group B strep)• Policies regarding universal newborn hepatitis B birth dose

administration

Independent Variables (Individual Level)

• Maternal factors – birth registry• Age (continuous)• Race/ethnicity (white non-Hispanic, black non-Hispanic, Hispanic,

other)• Education (less than high school, high school/GED, some college,

college degree and higher)• Insurance (private, Medicaid, self-pay)• Receipt of prenatal care (Y/N)• Attending provider (MD, DO, midwife)

• Infant factors – birth registry• Plurality (singleton, multiple)

Independent Variables (Hospital Level)

• Hospital Characteristics• Hospital size (≤ 500, > 500)• Urbanicity (urban, non-urban)• Written hospital vaccination policy (Y/N)

• Policy Survey

Dependent Variable

• Vaccination with hepatitis B vaccine prior to discharge (Y/N)

• Recorded on the birth certificate

Record Exclusion

• Excluded the following from analysis:• Infants weighing < 2,000 grams• Infants born outside of a hospital • Infants with unknown values for independent variables

Statistical Analysis

• Analyses were performed using SAS® 9.3• Bivariate associations assessed

• Birth dose and maternal/infant factors• Birth dose and hospital factors

• Stepwise multivariable logistic regression to assess the association of maternal, infant, and hospital level characteristics with infant hepatitis B immunization prior to discharge • Goodness-of-fit test and pseudo R2

Statistical Analysis

• Multilevel logistic regression analysis was performed• Level 1 – individual characteristics (maternal/infant)• Level 2 – hospital characteristics

• Preliminary results

RESULTS

Policy Survey

• Responses from 68 of 73 (93%) of hospitals

Policy85%

No Pol-icy

15%

Birth Dose Administration2009 Births

42,512

Birth Dose Administration2009 Births

42,512

Excluded 6,106 (14%)

Birth Dose Administration2009 Births

42,512

Excluded 6,106 (14%)

No Policy Survey4,340 (10%)

Birth Dose Administration2009 Births

42,512

Included in Analysis 32,066 (75%)

Excluded 6,106 (14%)

No Policy Survey4,340 (10%)

Birth Dose Administration2009 Births

42,512

Included in Analysis 32,066 (75%)

Received birth dose25,843 (80.6%)

Excluded 6,106 (14%)

No Policy Survey4,340 (10%)

Birth Dose Administration2009 Births

42,512

Included in Analysis 32,066 (75%)

Received birth dose25,843 (80.6%)

Excluded 6,106 (14%)

No Policy Survey4,340 (10%)

Received birth dose3,518 (81.1%)

Bivariate Analysis – Individual

• Maternal• Age• Education• Race/ethnicity• Attending provider• Prenatal care• Pay source

• Infant• Plurality

Bivariate Analysis – Individual

• Maternal• Age• Education• Race/ethnicity• Attending provider• Prenatal care• Pay source

• Infant• Plurality

Significant

Bivariate Analysis – Hospital

• Number of births• Urbanicity• Vaccination orders

Bivariate Analysis – Hospital

• Number of births• Urbanicity• Vaccination orders

Significant

• Individual factors• Age• Hispanic ethnicity• Maternal education• Private insurance• Plurality• Attending (DO)

• Hospital factors• Number of births• Urbanicity• Vaccination orders

GOF p = 0.67 Pseudo R2 = 0.25

Final Modelx2

Age (continuous) 29.2Race/Ethnicity (ref. White, non-Hispanic)

Black, non-Hispanic 2.7Hispanic 12.7Other 0.1

Education (ref. College Degree or Higher)Less than High School 45.2High School/GED 48.1Some College 14.7

Insurance (ref. Medicaid)Private 7.7Self-pay 0.1

Plurality (ref. Multiple)Singleton 46.9

Type of Attending (ref. MD)DO 4.1CNM/CM 0.1

Size (number of births) (ref. >500)≤500 129.0

Urbanicity (ref. Urban)Non-Urban 245.7

Vaccination Orders (ref. Yes)No orders 89.6

Logistic Regression

Significant: p < 0.05

Odds Ratio 95% CLAge (continuous) 0.98 0.98 – 0.99Race/Ethnicity (ref. White, non-Hispanic)

Black, non-Hispanic 1.14 0.99 – 1.31Hispanic 1.39 1.22 – 1.58Other 1.38 1.18 -1.62

Education (ref. College Degree or Higher)Less than High School 1.30 1.13 – 1.50High School/GED 1.34 1.20 – 1.49Some College 1.11 1.0 – 1.22

Insurance (ref. Medicaid)Private 1.01 0.91 – 1.11Self-pay 1.08 0.92 – 1.26

Plurality (ref. Multiple)Singleton 0.44 0.37 – 0.53

Prenatal Care (ref. Prenatal care)No prenatal care 1.50 1.05 – 1.14

Type of Attending (ref. MD)DO 0.98 0.84 – 1.13CNM/CM 0.84 0.69 – 1.02

Size (number of births) (ref. >500)≤500 0.70 0.25 – 1.99

Urbanicity (ref. Urban)Non-Urban 1.87 0.58 – 6.01

Vaccination Orders (ref. Yes)No orders 0.05 0.01 – 0.16

• Individual factors• Age• Hispanic ethnicity/other

race• High school education

or less• Plurality• Prenatal care

• Hospital factors• Vaccination orders

Multilevel Analysis

CONCLUSIONS

Discussion

• Maternal, infant, and hospital level characteristics are associated with receipt of the birth dose

• Disparities exist at both the individual and hospital level

Discussion

• Maternal education• Less education is significantly associated with birth dose

administration – higher educated women are more likely to question physicians

• Maternal race/ethnicity• Hispanic ethnicity and races other than white non-Hispanic

and black non-Hispanic are more likely to have vaccinated

• Plurality• Potentially due to greater involvement of physicians in

infants’ care as opposed to singletons?

Discussion

• No variation between urban and rural hospitals, or between large and small hospitals

• Vaccination orders• Presence of orders was most significantly associated with the

administration of the birth dose• Should be implemented at all hospitals

Limitations

• Birth dose data from the birth registry• Possible incorrect reports from hospitals

• No data on 5 hospitals’ policies • Multilevel analysis did not address interactions

Recommendations

• Educational efforts are needed regarding importance of the vaccine

• Continued education of hospitals on importance of birth dose

• Further examination of the multilevel logistic regression model is needed, including other hospital factors (e.g. teaching status, ownership type, etc.)

Acknowledgements

• Suparna Bagchi, PhD – EIS officer

• KDHE-BEPHI staff• Public Health Informatics• Infectious Disease Epidemiology and Response

• CSTE

Questions?

Healthy Kansans living in safe and sustainable environments.

www.kdheks.gov

Elizabeth Lawlor, MSAdvanced Epidemiologist

Bureau of Epidemiology and Public Health InformaticsKansas Department of Health and Environment

785-368-8208 [email protected]