Send to

Choose Destination
J Toxicol Environ Health B Crit Rev. 2017;20(8):390-422. doi: 10.1080/10937404.2017.1370847. Epub 2017 Sep 27.

Review of reviews on exposures to synthetic organic chemicals and children's neurodevelopment: Methodological and interpretation challenges.

Author information

a LaKind Associates , LLC , Catonsville , MD 21228 , USA.
b Department of Epidemiology and Public Health , University of Maryland School of Medicine , Baltimore , MD 21201 , USA.
c Center for Autism Spectrum Disorders, Children's National Health System , The George Washington University Medical Center , 15245 Shady Grove Road, Suite 350, Rockville , MD 20850 USA.
d Department of Epidemiology, Rollins School of Public Health , Emory University , 1518 Clifton Rd, Atlanta , GA 30322 USA.


Environmental epidemiology data are becoming increasingly important in public health decision making, which commonly incorporates a systematic review of multiple studies. This review addresses two fundamental questions: What is the quality of available reviews on associations between exposure to synthetic organic chemicals and neurodevelopmental outcomes? What is the value (e.g., quality and consistency) of the underlying literature? Published reviews on associations between synthetic organic environmental chemical exposures and neurodevelopmental outcomes in children were systematically evaluated. Seventy-four relevant reviews were identified, and these were evaluated with respect to four methodological characteristics: (1) systematic inclusion/exclusion criteria and reproducible methods for search and retrieval of studies; (2) structured evaluation of underlying data quality; (3) systematic assessment of consistency across specific exposure-outcome associations; and (4) evaluation of reporting/publication bias. None of the 74 reviews fully met the criteria for all four methodological characteristics. Only four reviews met two criteria, and six reviews fulfilled only one criterion. Perhaps more importantly, the higher quality reviews were not able to meet all of the criteria owing to the shortcomings of underlying studies, which lacked comparability in terms of specific research question of interest, overall design, exposure assessment, outcome ascertainment, and analytic methods. Thus, even the most thoughtful and rigorous review may be of limited value if the underlying literature includes investigations that address different hypotheses and are beset by methodological inconsistencies and limitations. Issues identified in this review of reviews illustrate considerable challenges that are facing assessments of epidemiological evidence.


Environmental chemical; PECO; epidemiology; neurodevelopment; systematic review

[Indexed for MEDLINE]

Supplemental Content

Loading ...
Support Center