Evidence map›Paper›PMID 42837416›Full record

ArticleInternational journal of epidemiology2026

Exposure misclassification of self-reported vegetarian diet and its impact on health outcomes.

Narges Ghoreishi, Tobias Kurth, Sven Knüppel, Matthew P Fox

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Article in International journal of epidemiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

4 authors.

Narges GhoreishiInstitute of Public Health, Charité-University Medical Center Berlin, Berlin, Germany.ORCID 0000-0003-4649-933X
Tobias KurthInstitute of Public Health, Charité-University Medical Center Berlin, Berlin, Germany.ORCID 0000-0001-7169-2620
Sven KnüppelDepartment of Food and Feed Safety in the Food Chain, German Federal Institute for Risk Assessment (BfR), Berlin, Germany.
Matthew P FoxDepartment of Epidemiology, Boston University School of Public Health, Boston, MA, United States.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundLiterature around the health impact of a vegetarian diet is expanding, yet exposure measurement and its effect on the study results receive far less attention. The aim of our study was to show the effect of bias from exposure misclassification on the direction, amount, and uncertainty of study results.

methodsWe included 11 180 participants from the National Health and Nutrition Examination Survey (2007-10). The exposure was self-reported diet type (being vegetarian). Using sensitivity, specificity, and positive and negative predictive values as bias parameters, we quantified the effect of exposure misclassification in non-differential and differential scenarios. We compared conventional analysis with bias-adjusted results.

resultsAmong self-reported vegetarians (2.2%), more than half (68%) reported consuming meat, poultry, or fish in the 24-hour dietary recalls. The sensitivity of self-reported diet type was 32% (95% CI, 0.26-0.38) and the specificity was 98% (95% CI, 0.98-0.99). The exposure misclassification was differential. The quantitative bias analysis of differential exposure misclassification was more informative. Using positive and negative predictive values as bias parameters was helpful to avoid negative bias-adjusted cell counts.

conclusionAssessing the impact of exposure misclassification in the self-reported vegetarian diet on four health outcomes, our study demonstrates that quantitative bias analysis can help to make more plausible assumptions about the possible direction, strength, and uncertainty of bias and its impact on the effect estimates of conventional analysis. However, comparing different scenarios showed that the model assumptions play a key role in the informative value of quantitative bias analysis.

Indexed as

Diet, VegetarianSelf ReportAdultAgedBiasFemaleHumansMaleMiddle AgedNutrition SurveysSensitivity and Specificitydietary recallsdifferential exposure misclassificationnegative predictive valuepositive predictive valuequantitative bias analysisself-reportsensitivity and specificityvegetarian diet

Identifiers

PMID42837416
PMCPMC13641060

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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.