A network analysis of the propagation of evidence regarding the effectiveness of fat-controlled diets in the secondary prevention of coronary heart disease (CHD): Selective citation in reviews

Abstract

ObjectiveTo examine how the first randomised controlled trials (RCTs) evaluating the efficacy of cholesterol-lowering diets in the secondary prevention of coronary heart disease were interpreted in reviews of the literature prior to the National Institutes of Health consensus conference in 1984.DesignClaim-specific citation network analysis was used to study the network of citations between reviews and RCTs over a defined period (1969–1984). RCTs were identified and classified according to whether their conclusions supported or opposed the use of dietary fat modification/restriction in the secondary prevention of coronary heart disease. Each review published in this period that cited any of the RCTs was classified as supportive, neutral, or unsupportive to the use of dietary fat modification based on a quotation analysis of its evaluation of the findings of these RCTs. Citation bias and underutilisation were detected by applying a comparative density measure, in-degree centrality, and out-degree in a series of sub-graph analyses.ResultsIn total, 66 unique publications were identified (four RCTs—one supportive, three unsupportive; 62 reviews—28 supportive, 17 neutral, 17 unsupportive). On average, supportive reviews underutilised the available RCTs to a greater degree than other reviews. Amongst the supportive group, citation bias was common—23 (82%) reviews cited only the one RCT that was supportive.ConclusionMost reviews that disseminated a supportive evaluation of the results of RCTs in the context of secondary prevention cited only data that supported this position.

Evidence for Citation Networks in Studies of Free-Roaming Cats: A Case Study Using Literature on Trap–Neuter–Return (TNR)

“…Critics of citation analysis note that many citations may be perfunctory or redundant, as opposed to significant ones that stimulate a new idea, provide a new method, or otherwise provide an integral part of the citing paper [ 79 ]. Authors may not even cite key influences on their work at all because they are not in a convenient citable form or because of ‘traditional non-citation’ for some sources such as established experimental or analytical techniques [ 5 ], or exercise conscious or sub-conscious bias in selecting studies to cite (for example, a tendency to cite positive studies more than negative ones is noted in fields as diverse as ecotoxicology [ 7 ], diagnostic imaging [ 80 ], and biomedical science [ 6 , 8 ]). Thus, the high citations reported are indicative of use, but not necessarily of quality.…”

“…However, even scientists are ‘human’ and, like others, may not be prepared to shift their position regardless of evidence: ‘Scientists, like everyone else, find it difficult to accept that which does not fit their beliefs, irrespective of the evidence’ ([ 5 ] p.480). Consequently, across diverse fields of science, the published literature contains biases against citation of negative studies that do not support an established hypothesis (e.g., [ 6 , 7 , 8 ]), with selective interpretation of literature to support a particular view [ 9 ]. There is also spin in scientific communication to the public.…”

The vasopressin−memory hypothesis: a citation network analysis of a debate

“…To understand the structure of the network, we generated a catalog of papers that were involved in the debate and classified them by whether they were supportive of the hypothesis or critical of it. This method has recently been used to study the structural dynamics of a number of scientific controversies . To catalog papers involved in the debate, we began with de Wied's most highly cited paper.…”

“…Here, we approached this controversy in a different way, by studying the evolution of the controversy through citation network analysis , compartmenting the network of interacting papers according to whether papers were supportive or critical of the vasopressin−memory hypothesis in the manner of a claim‐specific network (e.g., see Ref. ).…”

Preventing information distortion in the conservation literature

“…For example, authors may marginalise or ignore particular views when choosing papers to cite. This may be deliberate, or may arise from incomplete literature searches or relying on citation networks of supportive papers (Leng 2018). Authors may also refer to data in other papers but interpret it differently to the original authors -this isn't a problem if the different interpretation is acknowledged, but can be misleading if the implication is that the reinterpretation is the view of the original authors (Greenberg 2009).…”