Influenza vaccination coverage among pregnant women National 2009 H1N1 Flu Survey (NHFS) 2009-10 season Helen Ding, MD, MS,MSPH Epidemiologist, Chenega Government Consulting , LLC Contractor, Assessment Branch, Immunization Services Division, NCIRD, CDC National Immunization Conference Washington D. C. March 2011 National Center for Immunization & Respiratory Diseases Assessment Branch, Immunization Services Division

Acknowledgement CDC/NCIRD/Immunization Service Division Tammy A. Santibanez Gary L. Euler Peng-jun Lu James A. Singleton Cindy Weinbaum CDC/NCCDPHP/Division of reproductive health Denise J. Jamieson CDC/NCIRD/Influenza Division Lisa A. Grohskopf The whole talk is based on the paper that just been accepted for publication by American journal of Obstetrics and Gynecology. I would like acknowledge all our co-authors from AB, Influenza division and Division from Reproductive Health.

Background Pregnant women are at increased risk of morbidity and mortality from influenza because of physiological changes during pregnancy (Rasmussen, Jamieson and Bresee, Emerg Infect Dis 14:95-100, 2008) Influenza vaccination protects both pregnant women and their newborns from influenza and its complications (Zaman et al., N Engl J Med 359:1555-64, 2008; Eick A. et al, Arch Pediatri Adolesc Med 2010; DOI:10.1001/archpediatrics.2010.192.)

Vaccination recommendations Seasonal influenza vaccination was first recommended for pregnant women by the Surgeon General in the 1960s Since 2004, the Advisory Committee of Immunization Practice (ACIP) and American College of Ob/Gyn (ACOG) have recommended that all women who are or will be pregnant during the influenza season be vaccinated regardless of trimester For 2009-10 season, ACIP recommended all pregnant women should receive both 2009 H1N1 monovalent and seasonal trivalent vaccines. The recommendation for pregnant women has evolved with some variation over time regarding the strength and timing of the recommendation

Behavioral Risk Factor Surveillance Systems (BRFSS) Surveillance systems for vaccination pregnant women 2009-10 Influenza Season Behavioral Risk Factor Surveillance Systems (BRFSS) National Health Interview Survey (NHIS) Pregnancy Risk Assessment Monitoring System (PRAMS) National 2009 H1N1 Flu Survey (NHFS) As a response to pandemic, several surveillance systems were established or adapted to monitor influenza vaccination . Here I listed those that related to pregnant women. BRFSS is a state-based RDD household telephone survey. The pregnancy status were measured for all women 18-44 yrs old by a question asking whether they were currently pregnant during the interview. As pregnant women is a dynamic cohort, it didn’t capture the women that were pregnant during the flu season. NHIS is a national representative cross-sectional household survey. The pregnancy is also measured by the currently pregnancy status during interview. Because of the interview were conducted face-to face, it is considered as a gold standard for the estimates. But the data won’t available until at least a year post the influenza season. PRAMS is a mail-in survey that sampled from pregnant women who had a live birth. It contains birth certificate data. About 30 states participated the flu supplement survey in the 2009-10 season. It is the largest survey on pregnant women. However the data won’t available until at least 16 months post influenza season. National 2009 H1N1 flu survey

NHFS survey Random digit dial telephone survey October 2009 through June 2010 Landline Cell-phone only or mainly Collected both seasonal (trivalent) and 2009 H1N1 (monovalent) vaccination Measurement for pregnant women Women currently pregnant during interview Women that were pregnant any time October 2009 through January 2010

Influenza vaccination coverage estimates among pregnant women in years prior to 2009-10 1997-2008: Annual coverage estimates among currently pregnant women of NHIS* were 8%-19% Levels among other high-risk adults the same age were not even as low—18%-30%. National Health Interview Survey: 75% of interviews conducted in-person in the home. Women (n~190-370) were asked if they had received influenza vaccination in past 12 months . Interviews conducted Jan –Dec.

Objectives To assess influenza vaccination coverage among pregnant women for the pandemic season To compare vaccination coverage to non-pregnant women with high-risk conditions To examine factors associated with vaccination coverage

Methods Dataset : NHFS Interviews conducted April –June 2010 Study population: women 18-49 yrs old Pregnant women with other high-risk conditions (HRC) Pregnant women without other HRC Non-pregnant women with HRC Non-pregnant women without HRC High-risk conditions (HRC) refers to conditions included in the ACIP influenza recommendations that are associated with serious complications following influenza infection Pregnancy : Pregnant anytime October 2009-January 2010 Vaccination period: October 2009 - January 2010

Analyses Distributions of selected characteristics of the three groups of women Demographic characteristics Medical care utilization Personal opinions on infection and vaccines Univariate: vaccination coverage by above characteristics Multivariable analysis: Multiple logistic regression models for all women 18-49 yrs old Adjusted prevalence ratios based on adjusted coverage SAS 9.2 and SAS callable SUDDAN 10.0 used for analyses to take into account the complex survey design

Sample size 3,839 women 18-49 years old were selected for this study Pregnant women: 244 (6%) (50 with HRC, 194 without HRC) Non-pregnant women with HRC: 832 (21%) Non-pregnant women without HRC: 2,763 (73%)

SELECT RESULTS

Influneza vaccination coverage pregnant women

Vaccination coverage by three women groups

High-risk conditions: Influenza vaccination coverage among pregnant women

Race/ethnicity: Influenza vaccination coverage among pregnant women

Doctor’s recommendation: 2009 H1N1 vaccination coverage among three groups of women

Place of vaccination: among pregnant women

Reasons for not getting H1N1 vaccination: among pregnant women

Multivariable Analyses

Factors associated with 2009 H1N1 vaccination among all women 18-49 yrs

Factors associated with seasonal vaccination among all women 18-49 yrs *Adjusted for other covariates included n the model :HRC, income, and number of children in the household.

Summary About half of pregnant women received influenza vaccination in the 2009-10 season, much higher than coverages reported in previous seasons Pregnant women achieved higher vaccination level for H1N1 vaccine compared to non-pregnant women with/without HRC.

Summary Receipt of a health care provider’s recommendation for vaccination, perceived effectiveness of influenza vaccination, and perceived high chance of influenza infection were independently associated with higher H1N1 and seasonal vaccination.

Commentary The relative high coverage among pregnant women than the other two groups may due to the following reasons The effectiveness of public health massaging on the importance of influenza vaccination among pregnant women Extensive vaccination campaign and outreach efforts toward pregnant women care providers through new partnerships between CDC and provider communities The more exposure of pregnant women to health care providers because of prenatal care visits schedule

Commentary(con’t) In addition, compared to prior seasons, the dramatic increase of the coverage estimates among pregnant women for the 2009-10 season may in part due to the improvement of the measure of the pregnant women cohort that exposed to influenza season

Recommendations We achieved relatively higher vaccination coverage among pregnant women for the 2009-10 season, however it is still well below Healthy People 2020 goal of 90%, so Continued effort should be made to effectively deliver the message to pregnant women about the safety and effectiveness of the vaccines and the risk of flu to both themselves and their babies. The newly developed partnership with provider communities need to be strengthened to maintain and increase vaccination coverage among pregnant women.

Questions? Thanks! Helen Ding Hding@cdc.gov http://www.cdc.gov/flu/professionals/vaccination/vaccinecoverage.htm

Extra slides

Sample size Women 18-49 yrs Sample size Wgt'd % Total women 18-49 yrs   Sample size Wgt'd % Total women 18-49 yrs 3,839 100% Pregnant women 244 6% with HRC 50 Without HRC 194 Non-pregnant with HRC 832 21% Non-pregnant without HRC 2,763 73%

High-risk conditions: Influenza vaccination coverage among pregnant women-NHFS-2009-10 season

Education: Influenza vaccination coverage among pregnant women NHFS 2009-10 season %

Race/ethnicity: Influenza vaccination coverage among pregnant women NHFS 2009-10 season

Doctor’s recommendation: Influenza vaccination coverage among three groups of women

Influenza vaccination among three groups of women

Commentary (cont’) During the 2009-10 season new partnerships in the provider community serving pregnant women were developed. Extensive vaccination campaign and outreach efforts were conducted toward care providers for pregnant women through such partnerships to assure patient vaccination. Tailored communication messages based on focus groups conducted among pregnant women were utilized to develop posters and flyers. More accurate coverage measures were utilized such as asking women who were pregnant during the season about their vaccination during the season.

Limitations Sample size was relative small, which limited the abilities to run the multivariable model for pregnant women only Still we were not sure whether the vaccination was given before, during or after the pregnancy, though the vaccination period and the pregnancy period coincided

Attitudes toward influenza vaccination among pregnant women

Historically vaccination coverage repor