Evidence map›Paper›PMID 33605566›Full record

ArticleBirth defects research2021

Prepregnancy body mass index and spina bifida: Potential contributions of bias.

Candice Y Johnson, Margaret A Honein, Sonja A Rasmussen, Penelope P Howards, Matthew J Strickland, W Dana Flanders, National Birth Defects Prevention Study

Open access · greenAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Birth defects research, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
0.6field-weighted citation impact, top 30% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed, 4 citations in OpenAlex.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 4 institutions in 1 country.

Candice Y JohnsonDepartment of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.ORCID 0000-0002-2544-3110
Margaret A HoneinNational Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Sonja A RasmussenDepartment of Pediatrics and Epidemiology, University of Florida College of Medicine and College of Public Health and Health Professions, Gainesville, Florida, USA.ORCID 0000-0002-0574-4928
Penelope P HowardsDepartment of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
Matthew J StricklandSchool of Community Health Sciences, University of Nevada Reno, Reno, Nevada, USA.
W Dana FlandersDepartment of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
National Birth Defects Prevention Study
Centers for Disease Control and Prevention · USEmory University · USUniversity of Florida Health · USUniversity of Nevada, Reno · US

Funding

CDC HHS PA #02081CDC HHS PA #96043Centers for Birth Defects Research and Prevention FOA #DD09-001Intramural CDC HHS CC999999
6 · The paper itself

Abstract

backgroundEpidemiologists have consistently observed associations between prepregnancy obesity and spina bifida in offspring. Most studies, however, used self-reported body mass index (potential for exposure misclassification) and incompletely ascertained cases of spina bifida among terminations of pregnancy (potential for selection bias). We conducted a quantitative bias analysis to explore the potential effects of these biases on study results.

methodsWe included 808 mothers of fetuses or infants with spina bifida (case mothers) and 7,685 mothers of infants without birth defects (control mothers) from a population-based case-control study, the National Birth Defects Prevention Study (1997-2011). First, we performed a conventional epidemiologic analysis, adjusting for potential confounders using logistic regression. Then, we used 5,000 iterations of probabilistic bias analysis to adjust for the combination of confounding, exposure misclassification, and selection bias.

resultsIn the conventional confounding-adjusted analysis, prepregnancy obesity was associated with spina bifida (odds ratio 1.4, 95% confidence interval: 1.2, 1.7). In the probabilistic bias analysis, we tested nine different models for the combined effects of confounding, exposure misclassification, and selection bias. Results were consistent with a weak to moderate association between prepregnancy obesity and spina bifida, with the median odds ratios across the nine models ranging from 1.1 to 1.4.

conclusionsGiven our assumptions about the occurrence of bias in the study, our results suggest that exposure misclassification, selection bias, and confounding do not completely explain the association between prepregnancy obesity and spina bifida.

Indexed as

Spinal DysraphismBiasBody Mass IndexCase-Control StudiesFemaleHumansOdds RatioPregnancybiasbody mass indexneural tube defectsobesityspina bifida

Identifiers

PMID33605566
PMCPMC8358821
OpenAlexW3130987773

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.