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]