Maternal and Child Health Journal

, Volume 8, Issue 2, pp 77–86

A Comparative Analysis of Effects of Early Versus Late Prenatal WIC Participation on Birth Weight: NYS, 1995

  • Victoria Lazariu-Bauer
  • Howard Stratton
  • Robert Pruzek
  • Mary Lou Woelfel
Article

Abstract

Objectives: This study examined the effects of prenatal participation in the NYS WIC Program on birth weight through enhanced control of selection bias and gestational age bias. Program effects were assessed separately for White, Black, and Hispanic women and subpopulations defined by values of Kotelchuck index of adequacy of prenatal care utilization. Methods: 1995 New York State Vital Statistics records were linked to WIC certifications, administrative and check redemption files, and to the 1990 federal census of NY county level data. The final data set contained 77,601 records. Birth weight among WIC participants who enrolled early and participated longer were compared to those who enrolled late and participated a shorter time. Selection bias was addressed using classification tree methods as part of a propensity score analysis. Gestational age bias was addressed by analyzing preterm and full-term pregnancies separately. Results: Adjusted estimates showed a significant positive effect of longer prenatal WIC participation on birth outcomes for all groups studied. Infants born to WIC participants who enrolled early were heavier than those who enrolled late by, on average, 70 g for full-term and 129 grams for preterm. Black and Hispanic full-term infants experienced larger WIC effects than Whites (79, 75, 43 g, respectively). Looking at full-term pregnancies using Kotelchuck's index indicated that effects of longer prenatal WIC participation were greatest for the inadequate prenatal care group (83 g). Conclusion: Longer prenatal WIC participation was associated with an increase in birth weight overall and for all groups studied. The effect on birth weight of longer participation in WIC was greatest in Black and Hispanic, inadequate and no prenatal care groups.

WIC participation selection bias propensity score analysis classification trees gestational bias race/ethnicity prenatal care 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

REFERENCES

  1. 1.
    Buescher PA, Stephanie JH. Prenatal WIC participation in relation to low birth weight and medicaid infant costs in North Carolina—A 1997 update. J Am Diet Assoc 2001;101(9): 997.Google Scholar
  2. 2.
    Ahluwalia IB, Hogan VK, Grummer-Strawn L, Colville WR, Peterson A. The effect of WIC participation on small-for-gestational-age births: Michigan, 1992. Am J Public Health 1998;88(9):1374–7.Google Scholar
  3. 3.
    Early intervention: Federal investments like WIC can produce savings. Gaithersburg, MD: US General Accounting Office, GAO publication HRD-92-18, 1992.Google Scholar
  4. 4.
    Devaney B, Bilheimer L, Schore J. The savings in Medicaid costs for newborns and their mothers from prenatal participation in the WIC Program, Volume 1. Washington, DC: U.S. Department of Agriculture, Food and Nutrition Service, Office of Analysis and Evaluation, October 1990.Google Scholar
  5. 5.
    Devaney B, Bilheimer L, Schore J. The savings in Medicaid costs for newborns and their mothers from prenatal participation in the WIC Program, Volume 2. Washington, DC: U.S. Department of Agriculture, Food and Nutrition Service, Office of Analysis and Evaluation, April 1991.Google Scholar
  6. 6.
    Stockbauer JW. Evaluation of the Missouri WIC program: Prenatal components. J Am Diet Assoc 1986;86(1):61–7.Google Scholar
  7. 7.
    Stockbauer JW. WIC prenatal participation and its relation to pregnancy outcomes in Missouri: A second look. Am J Public Health 1987;77(7):813–8.Google Scholar
  8. 8.
    Kotelchuck M, Schwartz JB, Anderka MT, Finison KS. WIC participation and pregnancy outcomes: Massachusetts Statewide Evaluation Project. Am J Public Health 1984;74(10):1086–92.Google Scholar
  9. 9.
    Edozien J, Switzer B, Bryan R. Medical evaluation of the Special Supplemental Food Program for Women, Infants and Children. Am J Clin Nutr 1979;32(3):677–92.Google Scholar
  10. 10.
    Rush D, Sloan NL, Leighton J, Alvir JM, Horvitz DG, Seaver WB, et al. The National WIC Evaluation: Evaluation of the Special Supplemental Food Program for Women, Infants, and Children. V. Longitudinal study of pregnant women. Am J Clin Nutr 1988;48(2 Suppl.):439–83.Google Scholar
  11. 11.
    Devaney B, Schirm A. Infant mortality among Medicaid newborns in five states: The effects of prenatal WIC participation. Washington, DC: U.S. Department of Agriculture, Food and Nutrition Service, Office of Analysis and Evaluation, May 1993.Google Scholar
  12. 12.
    Kowaleski-Jones L, Duncan GJ. Effects of participation in the WIC program on birthweight: Evidence from the National Longitudinal Survey of Youth. Am J Public Health 2002;92;799–804.Google Scholar
  13. 13.
    Gordon A, Nelson L. Characteristics and outcomes of WIC participants and nonparticipants: Analysis of the 1988 National Maternal and Infant Health Survey. Princeton, NJ: Mathematica Policy Research, Reference No. 7939-011, 1995.Google Scholar
  14. 14.
    Rush D. Is WIC worthwhile? Am J Public Health 1982;72;1101–03.Google Scholar
  15. 15.
    Rush D. Some comments on the Massachusetts WIC Evaluation. Am J Public Health 1984;74;1145–48.Google Scholar
  16. 16.
    U.S. General Accounting Office. WIC evaluations provide some favorable but no conclusive evidence on the effects expected for the Special Supplemental Program for Women, Infants, and Children. GAO/PEMD-84-4. Washington, DC: Author, 1984.Google Scholar
  17. 17.
    Oliveira V, Racine E, Olmsted J, Ghelfi LM. The WIC Program: Background, trends, and issues. Washington, DC: U.S. Department of Agriculture, Economic Research Service, Food Assistance and Nutrition Research Report Number 27.Google Scholar
  18. 18.
    Besharov DJ, Germanis P. Rethinking WIC: An evaluation of the women, infants, and children program. Washington DC: The AEI Press, 2001.Google Scholar
  19. 19.
    Lazariu-Bauer V. New methods for propensity score adjustment to selection bias for WIC prenatal effects. PhD Thesis, State University of New York, University at Albany.Google Scholar
  20. 20.
    Rubin DB. Estimating causal effects from large data sets using propensity scores. Ann Intern Med 1997;127:757–63.Google Scholar
  21. 21.
    Rosenbaum PR, Rubin DB. The central role of the propensity score in observational studies for causal effects. Biometrika 1983;70:41–55.Google Scholar
  22. 22.
    Rosenbaum PR. Observational studies. New York: Springer-Verlag, 1995.Google Scholar
  23. 23.
    D'Agostino RB, Jr. Tutorial in biostatistics: Propensity score methods for bias reduction in the comparison of a treatment to a non-randomized control group. Stat Med. 1998;17: 2265–81.Google Scholar
  24. 24.
    Kotelchuck M. An evaluation of the Kessner adequacy of prenatal care index and a proposed adequacy of prenatal care utilization index. Am J Public Health 1994;84(9):1414–20.Google Scholar
  25. 25.
    Kotelchuck M. Adequacy of prenatal care utilization index. SAS computational program. Version (3). Available from: http://www.healthystart.net/hssite_into/apncu_index.htmGoogle Scholar
  26. 26.
    The visible embryo. Available from: http://www.visembryo.comGoogle Scholar
  27. 27.
    Herrera GA, Smith P, Daniels D, Monina Klevens R, Coronado V, McCauley M, et al. National, state, and urban area vaccination coverage levels among children aged 19–35 months—United States, 1998. Mortal Wkly Rep CDC Surveill Summ. 2000;49(SS-9):1–25.Google Scholar
  28. 28.
    Smith PJ, Rao JNK, Battaglia MP, Ezzati-Rice TM, Daniels D, Khare M. Compensating for provider nonresponse using response propensities to form adjustment cells: The National Immunization Survey. Vital Health Stat 2. 2001;133.Google Scholar
  29. 29.
    Efron B, Tibshirani RJ. An introduction to the bootstrap. New York: Chapman & Hall, 1993.Google Scholar
  30. 30.
    U.S. Department of Health and Human Services, Office of Disease Prevention and Health Promotion. Healthy people 2010, 2nd ed. Washington, DC: US Government Printing Office, 2000.Google Scholar
  31. 31.
    Lu MC, Halfon N. Racial and ethnic disparities in birth outcomes: A life-course perspective. Matern Child Health J. 2003; 7(1):13–30.Google Scholar

Copyright information

© Plenum Publishing Corporation 2004

Authors and Affiliations

  • Victoria Lazariu-Bauer
    • 1
  • Howard Stratton
    • 2
  • Robert Pruzek
    • 2
  • Mary Lou Woelfel
    • 1
  1. 1.New York State Department of Health, Division of Nutrition, Evaluation and Analysis UnitNew York
  2. 2.Department of Epidemiology and Biostatistics, School of Public HealthState University of New York, University at AlbanyNew York

Personalised recommendations