To date, there is no comprehensive analysis of the relationship between financial conflict of interest (COI) and a potential publication bias in environmental and occupational health studies.
We analyzed original research articles published in 2012 in 17 peer-reviewed journals. Multivariable ordinal logistic regression models were developed to evaluate the relationship between financial COI and the study outcome.
Of the 373 studies included in the analysis, 17.2% had a financial COI associated with organizations involved with the processing, use, or disposal of industrial and commercial products, and studies with this type of COI were more likely to report negative results (Adjusted Odds Ratio = 4.31), as were studies with any COI associated with the military (employment or funding; Adjusted Odds Ratio = 9.15).
Our findings show a clear relationship between direction of reported findings and specific types of financial COI.