Exploring the Influence of Alcohol Industry Funding in Observational Studies on Moderate Alcohol Consumption and Health

Alcohol, cardiovascular disease and industry funding: A co-authorship network analysis of epidemiological studies

INTRODUCTION

Alcohol's effects on cardiovascular disease (CVD) are controversial. Alcohol industry actors have shown particular interest in this subject, and been extensively involved through research funding, and in other ways, generating concerns about bias, particularly in reviews.

MATERIAL & METHODS

We conducted a co-authorship network analysis of the primary studies included within a previous co-authorship study of 60 systematic reviews on the impact of alcohol on CVD. Additionally, we examined the relationships between declared alcohol industry funding and network structure.

RESULTS

There were 713 unique primary studies with 2832 authors published between 1969 and 2019 located within 229 co-authorship subnetworks. There was industry funding across subnetworks and approximately 8% of all papers declared industry funding. The largest subnetwork dominated, comprising 43% of all authors, with sparse evidence of substantial industry funding. The second largest subnetwork contained approximately 4% of all authors, with largely different industry funders involved. Harvard affiliated authors who at the review level formed co-authorship subnetworks with industry funded authors were seen at the primary study level to belong to the largest epidemiological subnetwork. A small number of key authors make extensive alcohol industry funding declarations.

CONCLUSIONS

There was no straightforward relationship between co-authorship network formation and alcohol industry funding of epidemiological studies on alcohol and CVD. More fine-grained attention to patterns of alcohol industry funding and to key nodes may shed further light on how far industry funding may be responsible for conflicting findings on alcohol and CVD.

Alcohol, cardiovascular disease and industry funding: A co-authorship network analysis of systematic reviews

BACKGROUND

Alcohol's effects on heart health is the site of a major scientific controversy. We conducted a co-authorship network analysis of systematic reviews on the impacts on alcohol on cardiovascular disease (CVD) in order to investigate patterns of co-authorship in the literature, with particular attention given to industry funding.

METHODS

We used Epistemonikos to identify systematic reviews. Review characteristics, influential authors, co-authorship subnetworks, prior histories of alcohol industry funding, study outcomes and citations were investigated.

RESULTS

60 systematic reviews with 231 unique authors met our inclusion criteria. 14 systematic reviews were undertaken by authors with histories of alcohol industry funding, including 5 that were funded directly by the alcohol industry itself. All 14 such reviews identified a cardioprotective effect of alcohol. These formed distinct co-authorship subnetworks within the literature. Of reviews by authors with no prior histories of alcohol industry funding, the findings were mixed, with 54% (25/46) concluding there was evidence of health protective effects. These two groups of reviews differed in other respects. Those with industry funding were more likely to study broader outcomes such as 'cardiovascular disease' or 'coronary heart disease' as opposed to specific CVD issues such as hypertension or stroke (93% [13/14] versus 41% [19/46]) (chi-squared 12.4, p < 0.001) and have more included studies (mean of 29 versus 20). They were also more widely cited by others. Over time the proportions of systematic reviews on CVD and alcohol undertaken by authors with no prior histories of alcohol industry funding has increased.

CONCLUSIONS

Systematic reviews undertaken by authors with histories of alcohol industry funding were more likely to study broader outcomes, and be cited more widely, and exclusively reported favorable conclusions.

Doubly Photopolymerized Holographic Sensors

Holographic sensors are two-dimensional (2D) photonic crystals that diffract narrow-band light in the visible spectrum to quantify analytes in aqueous solutions. Here, a holographic fabrication setup was developed to produce holographic sensors through a doubly polymerization system of a poly-2-hydroxyethyl methacrylate hydrogel film using a pulsed Nd:YAG laser (λ = 355 nm, 5 ns, 100 mJ). Wavelength shifts of holographic Bragg peak in response to alcohol species (0-100 vol %) were characterized. Diffraction spectra showed that the holographic sensors could be used for short-chain alcohols at concentrations up to 60 vol %. The reversibility of the sensor was demonstrated, exhibiting a response time of 7.5 min for signal saturation. After 30 cycles, the Bragg peak and color remained the same in both 20 and 60 vol %. The fabrication parameters were simulated in MATLAB using a 2D finite-difference time-domain algorithm to model the interference pattern and energy flux profile of laser beam recording in the hydrogel medium. This work demonstrates a particle-free holographic sensor that offers continuous, reversible, and rapid colorimetric readouts for the real-time quantification of alcohols.