Do small effects matter more in vulnerable populations? an investigation using Environmental influences on Child Health Outcomes (ECHO) cohorts

Janet L Peacock; Susana Diaz Coto; Judy R Rees; Odile Sauzet; Elizabeth T Jensen; Raina Fichorova; Anne L Dunlop; Nigel Paneth; Amy Padula; Tracey Woodruff; Rachel Morello-Frosch; Jessica Trowbridge; Dana Goin; Luis E Maldonado; Zhongzheng Niu; Akhgar Ghassabian; Leonardo Transande; Assiamira Ferrara; Lisa A Croen; Stacey Alexeeff; Carrie Breton; Augusto Litonjua; Thomas G O'Connor; Kristen Lyall; Heather Volk; Akram Alshawabkeh; Justin Manjourides; Carlos A Camargo Jr; Dana Dabelea; Christine W Hockett; Casper G Bendixsen; Irva Hertz-Picciotto; Rebecca J Schmidt; Alison E Hipwell; Kate Keenan; Catherine Karr; Kaja Z LeWinn; Barry Lester; Marie Camerota; Jody Ganiban; Cynthia McEvoy; Michael R Elliott; Sheela Sathyanarayana; Nan Ji; Joseph M Braun; Margaret R Karagas; Program Collaborators for Environmental influences on Child Health Outcomes

doi:10.1186/s12889-024-20075-x

Do small effects matter more in vulnerable populations? an investigation using Environmental influences on Child Health Outcomes (ECHO) cohorts

BMC Public Health. 2024 Sep 28;24(1):2655. doi: 10.1186/s12889-024-20075-x.

Authors

Janet L Peacock¹, Susana Diaz Coto², Judy R Rees², Odile Sauzet³, Elizabeth T Jensen⁴, Raina Fichorova⁵, Anne L Dunlop⁶, Nigel Paneth⁷, Amy Padula⁸, Tracey Woodruff⁸, Rachel Morello-Frosch⁹, Jessica Trowbridge⁸, Dana Goin¹⁰, Luis E Maldonado¹¹, Zhongzheng Niu¹¹, Akhgar Ghassabian¹², Leonardo Transande¹³, Assiamira Ferrara¹⁴, Lisa A Croen¹⁴, Stacey Alexeeff¹⁴, Carrie Breton¹¹, Augusto Litonjua¹⁵, Thomas G O'Connor¹⁵, Kristen Lyall¹⁶, Heather Volk¹⁷, Akram Alshawabkeh¹⁸, Justin Manjourides¹⁸, Carlos A Camargo Jr¹⁹, Dana Dabelea²⁰, Christine W Hockett^{21

22}, Casper G Bendixsen²³, Irva Hertz-Picciotto²⁴, Rebecca J Schmidt²⁴, Alison E Hipwell²⁵, Kate Keenan²⁶, Catherine Karr²⁷, Kaja Z LeWinn²⁸, Barry Lester²⁹, Marie Camerota²⁹, Jody Ganiban³⁰, Cynthia McEvoy³¹, Michael R Elliott³², Sheela Sathyanarayana^{33

34

35}, Nan Ji¹¹, Joseph M Braun³⁶, Margaret R Karagas²; Program Collaborators for Environmental influences on Child Health Outcomes

Collaborators

Program Collaborators for Environmental influences on Child Health Outcomes:
P B Smith, L K Newby, L P Jacobson, D J Catellier, R Gershon, D Cella, J Cordero, J Meeker, L Gatzke-Kopp, M Swingler, J M Mansbach, J M Spergel, M E Samuels-Kalow, M D Stevenson, C S Bauer, D Koinis Mitchell, S Deoni, V D 'Sa, C S Duarte, C Monk, J Posner, G Canino, A J Elliott, J Gern, R Miller, E Zoratti, C Seroogy, D Jackson, L Bacharier, M Kattan, R Wood, K Rivera-Spoljaric, G Hershey, T Hartert, C Johnson, D Ownby, A Singh, T Bastain, S Farzan, R Habre, F Tylavsky, A Mason, Q Zhao, N Bush, K Z LeWinn, B Carter, S Pastyrnak, C Neal, L Smith, J Helderman, L Leve, J Neiderhiser, S T Weiss, G O Connor, R Zeiger, R Tepper, R Landa, S Ozonoff, S Dager, R Schultz, J Piven, H Simhan, C Buss, P Wadhwa, K Huff, R K Miller, E Oken, J M Kerver, C Barone, C Fussman, M Elliott, D Ruden, J Herbstman, S Schantz, J Stanford, C Porucznik, A Giardino, R J Wright, M Bosquet-Enlow, K Huddleston, R Nguyen, E Barrett, S Swan, F Perera

Affiliations

¹ Department of Epidemiology, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH, 03756, USA. janet.l.peacock@dartmouth.edu.
² Department of Epidemiology, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH, 03756, USA.
³ Bielefeld School of Public Health and Department of Economy and Business Administration, Bielefeld University, Bielefeld, Germany.
⁴ Department of Epidemiology and Prevention, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
⁵ Department of Gynecology and Reproductive Biology, Brigham and Women's Hospital, Boston, MA, USA.
⁶ Emory University School of Medicine, Atlanta, GA, USA.
⁷ Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI, USA.
⁸ Department of Reproductive Sciences, School of Medicine, University of California San Francisco, San Francisco, CA, USA.
⁹ Department of Environmental Health Sciences, University of California, Berkeley, CA, USA.
¹⁰ Children's Environmental Health Center, University of Illinois, Urbana, IL, USA.
¹¹ Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
¹² Harvard TH Chan School of Public Health, Harvard University, Boston, MA, USA.
¹³ Department of Pediatrics, NYU Grossman School of Medicine, New York, NY, USA.
¹⁴ Kaiser Permanente Northern California Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA.
¹⁵ University of Rochester Medical Center, Rochester, NY, USA.
¹⁶ AJ Drexel Autism Institute, Drexel University, Philadelphia, PA, USA.
¹⁷ Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
¹⁸ Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, USA.
¹⁹ Department of Emergency Medicine, Massachusetts General Hospital, Boston, MA, USA.
²⁰ Lifecourse Epidemiology of Adiposity and Diabetes (LEAD) Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
²¹ Avera Research Institute, Sioux Falls, SD, USA.
²² Department of Pediatrics, University of South Dakota School of Medicine, Sioux Falls, SD, USA.
²³ National Farm Medicine Center, Marshfield Clinic Research Institute, Marshfield, WI, USA.
²⁴ Department of Public Health Sciences, School of Medicine, The MIND Institute, University of California Davis, Davis, CA, USA.
²⁵ Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA.
²⁶ University of Chicago, Chicago, IL, USA.
²⁷ Department of Pediatrics, University of Washington, Seatle, WA, USA.
²⁸ Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA, USA.
²⁹ Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University, Brown University, Providence, RI, USA.
³⁰ George Washington University, Washington, DC, USA.
³¹ Department of Pediatrics, School of Medicine, Oregan Health and Science University, Portland, OR, USA.
³² University of Michigan School of Public Health and Institute for Social Research, University of Michigan, Ann Arbor, MI, USA.
³³ Department of Pediatrics, Center for Child Health, Behavior, and Development, Seattle Children's Research Institute, Seattle, WA, USA.
³⁴ Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, USA.
³⁵ Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA, USA.
³⁶ Warren Alpert Medical School of Brown University, Brown University, Providence, RI, USA.

Abstract

Background: A major challenge in epidemiology is knowing when an exposure effect is large enough to be clinically important, in particular how to interpret a difference in mean outcome in unexposed/exposed groups. Where it can be calculated, the proportion/percentage beyond a suitable cut-point is useful in defining individuals at high risk to give a more meaningful outcome. In this simulation study we compute differences in outcome means and proportions that arise from hypothetical small effects in vulnerable sub-populations.

Methods: Data from over 28,000 mother/child pairs belonging to the Environmental influences on Child Health Outcomes Program were used to examine the impact of hypothetical environmental exposures on mean birthweight, and low birthweight (LBW) (birthweight < 2500g). We computed mean birthweight in unexposed/exposed groups by sociodemographic categories (maternal education, health insurance, race, ethnicity) using a range of hypothetical exposure effect sizes. We compared the difference in mean birthweight and the percentage LBW, calculated using a distributional approach.

Results: When the hypothetical mean exposure effect was fixed (at 50, 125, 167 or 250g), the absolute difference in % LBW (risk difference) was not constant but varied by socioeconomic categories. The risk differences were greater in sub-populations with the highest baseline percentages LBW: ranging from 3.1-5.3 percentage points for exposure effect of 125g. Similar patterns were seen for other mean exposure sizes simulated.

Conclusions: Vulnerable sub-populations with greater baseline percentages at high risk fare worse when exposed to a small insult compared to the general population. This illustrates another facet of health disparity in vulnerable individuals.

Keywords: Child health outcome; Environmental exposure; Health disparities; Pregnancy outcomes; Social determinants of health.

MeSH terms

Adult
Birth Weight*
Child Health* / statistics & numerical data
Cohort Studies
Environmental Exposure / adverse effects
Female
Humans
Infant, Low Birth Weight*
Infant, Newborn
Male
Pregnancy
Socioeconomic Factors
Vulnerable Populations* / statistics & numerical data