1. Infant Feeding Practices Study II Methods American Public Health Association November 5, 2007 Sara B. Fein, Judith Labiner-Wolfe, Katherine Shealy, Ruowei Li, Laurence Grummer-Strawn Food and Drug Administration and Centers for Disease Control and Prevention

2. Overview The Infant Feeding Practices Study II (IFPS II) is a longitudinal, prospective study of pregnant women and new mothers Data collected by self-administered mail questionnaires Based on IFPS I (1993-1994)

3. Data Collection Design Data collected from the same women from pregnancy through the entire first year of infant’s life 2 prenatal and 12 postnatal data collections Two types of data collected –Infant feeding and other infant care practices –Mothers’ dietary intake during pregnancy and about 4 months postpartum

4. Data Collection Timeline Questionnaires were mailed from May 2005 through March 2007 Infant feeding was assessed about every month for the first 7 months and then about every 7 weeks through infant age 12 months Data collected for each questionnaire over a period of 8 months –For example, the prenatal questionnaire was sent every month from May through December

5. Study Sponsors Food and Drug Administration is the overall lead agency in close collaboration with Centers for Disease Control and Prevention Funding (data collection) –Centers for Disease Control and Prevention –Office on Woman’s Health –National Institute of Health –Health Resources and Services Administration –Food and Drug Administration

6. Questionnaire Development Questionnaires were developed in consultation with a working group All funding partners Economic Research Service/USDA National Center for Health Statistics Academicians who had worked on 1 st IFPS Maternal Dietary Intake used National Cancer Institute’s Diet History Questionnaire Modified for 1-month time frame Added foods of interest in pregnancy

7. Questionnaire Development Questionnaires were extensively tested Cognitive interviews Pilot tests Protocol approved by Office of Management and Budget and by FDA’s Research Involving Human Subjects Committee

8. Infant Questionnaire Topics Prenatal Mother’s health and health care; breastfeeding attitudes, experience, plans Neonatal Birth experience Breastfeeding practice and support in the hospital and after discharge Mother’s knowledge, attitudes, confidence, and planned duration of breastfeeding Reasons for not trying to breastfeed

9. Infant Questionnaire Topics - Postnatal Postnatal Questionnaires (not all topics asked every time) Food frequency checklist, dietary supplement and herbal intake, and health problems of infants Stopped Breastfeeding: age, reasons Infant formula feeding and breastfeeding details Food allergy Information sources Sleeping arrangements Mother’s employment and child care Mother’s health, weight, and tobacco use

10. Sample Sample is drawn from an established consumer opinion panel of about 500,000 households Sample size is 4,900 pregnant women, 3,000 mothers of 1-month old infants, and about 2,000 mothers of older infants Sample size for mother’s dietary intake was limited to about 1,400

11. Sample Criteria Mothers > 18 years of age when recruited Singleton infant Birth weight > 5 pounds Full term or near-term infants (>35 weeks) Infants with no NICU or < 3 day stay Mother and infant healthy at birth Infant had no long term medical condition that would affect feeding

12. Sample Evaluation IFPS II sample was compared with nationally representative sample of new mothers Comparison sample was 2002 National Survey of Family Growth (1998-2000 births)

13. Sample characteristics compared to the National Survey of Family Growth *P<.05Percent of IFPS II sample (2005-2006 births) Percent of NSFG sample(1998-2000 births) Mother’s age (18-24)*23.332.6 Race/ethnicity (White)*84.461.5 Education (HS or less)*21.047.5 % Poverty (185-350)*35.827.4 Primiparous*29.225.3 Married79.179.5 Employed *66.361.2 Ever breastfed*85.367.8 Exclusive breastfed 3 m34.335.1 1 st prenatal care <13 w*88.691.9

14. Conclusions from Sample Evaluation IFPS II sample over-represents older mothers, whites, higher educated, and middle income IFPS II sample is not necessarily different on health and attitude characteristics

15. Response Rates Questionnaire# CompletesResponse Rate Prenatal 4,902 Can’t estimate Birth screener 3,448 70.3 Neonatal3,03388.0 Month 22,55384.2 Month 52,18572.0 Month 121,80759.6 Missed 0 q1,17238.7 Total missed 0-3 q2,00166.0

16. Study Limitations Sample is not nationally representative All data are reported by the mother –No medical records Dietary data for infants are for food groups only, not specific foods No portion sizes for infants

17. Study Strengths Longitudinal and prospective design Extensive questionnaire development Detailed data Short recall period Relatively high response rate over time Large sample size Sample is well distributed throughout the US

18. Conclusion The IFPS II data cover a wide range of topics related to infant feeding and health The IFPS II has a valuable and unique data set about infant feeding and dietary intake of pregnant women and new mothers Web site: www.cdc.gov/ifps