Evidence map›Paper›PMID 24645904›Full record

SynthesisClinical toxicology (Philadelphia, Pa.)2014

Does diisocyanate exposure result in neurotoxicity?

M A Hughes, M Carson, M A Collins, A T Jolly, D M Molenaar, W Steffens, G M H Swaen

Abstract readSystematic Review
In one paragraph

Synthesis in Clinical toxicology (Philadelphia, Pa.), 2014. 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
–field-weighted citation impact
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.

  1. Review
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.

M A HughesUniversity of Utah Rocky Mountain Center for Occupational and Environmental Health , Salt Lake City, UT , USA.
M Carson
M A Collins
A T Jolly
D M Molenaar
W Steffens
G M H Swaen

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

contextDiisocyanates have been associated with respiratory and dermal sensitization. Limited number of case reports, and a few case studies, media, and other references suggest potential neurotoxic effects from exposures to toluene diisocyanate (TDI), 1,6 hexamethylene diisocyanate (HDI), and methylene diisocyanate (MDI). However, a systematic review of the literature evaluating the causal association on humans does not exist to support this alleged association.

objectiveTo perform systematic review examining the body of epidemiologic evidence and provide assessment of causal association based on principles of the Sir Austin Bradford Hill criteria or considerations for causal analysis.

methodsA comprehensive search of public databases for published abstracts, case reports, cross-sectional surveys, and cohort studies using key search terms was conducted. Additional searches included regulatory reviews, EU IUCLID and EU Risk Assessment databases, and unpublished reports in the International Isocyanate Institute database. An expert panel consisting of physicians, toxicologists, and an epidemiologist critically reviewed accepted papers, providing examination of epidemiologic evidence of each report. Finally, the Hill criteria for causation were applied to the summative analysis of identified reports to estimate probability of causal association.

resultsTwelve papers reporting exposed populations with a variety of neurological symptoms or findings suitable for analysis were identified, including eleven case or case series reports, and one cross-sectional study. Three papers reported on the same population. Each of the papers was limited by paucity of diisocyanate exposure estimates, the presence of confounding exposures to known or suspected neurotoxicants, a lack of objective biological measures of exposure or neurotoxic effects, and lack of relative strength of association measures. Additionally, reported health symptoms and syndromes lacked consistency or specificity. No plausible mechanism of toxicity was found. Application of a predictive mathematical model for determining probability of causal association for neurotoxicity was calculated to be 21%.

conclusionThere is insufficient evidence for a causal association of neurotoxic effects and diisocyanate exposure based on lack of evidence in all categories of the Hill criteria for causality except for temporal association of reported symptoms and alleged exposure. Future reports should attempt to address more rigorous exposure assessment and control for confounding exposures.

Indexed as

Evidence-Based PracticeAnimalsCausalityCentral Nervous System AgentsEcotoxicologyEnvironmental ExposureEnvironmental PollutantsGuidelines as TopicHumansIsocyanatesNeurotoxicity SyndromesOccupational ExposurePeripheral Nervous System AgentsToluene 2,4-Diisocyanate1,6-hexamethylene diisocyanateCentral Nervous System AgentsEnvironmental PollutantsIsocyanatesmethylene diisocyanatePeripheral Nervous System AgentsToluene 2,4-Diisocyanate

Identifiers

PMID24645904
PMCPMC4025582

What OpenQuestion holds

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Registered trials

None linked

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.