Abstract
Context:
The misrepresentation and distortion of research findings, known as “spin,” has been shown to affect clinical decision making. Spin has been found in randomized controlled trials (RCTs) published in various fields of medicine.
Objective:
To evaluate the abstracts of RCTs found in the cardiology literature for spin.
Methods:
The authors searched PubMed using a specific string of keywords to identify previously published articles documenting RCTs of cardiovascular treatments in humans. To be included, a cardiology trial had to randomize humans to an intervention, statistically compare 2 or more groups, and have a nonsignificant primary endpoint. Records were excluded if they did not meet these criteria. Data extraction was double-blinded and done using a pilot-tested Google Form. Items extracted from each trial included the title, journal, funding source, comparator arm, primary endpoint, statistical analysis of the primary endpoint, secondary endpoints, statistical analysis of secondary endpoints, and trial registration number (if reported). The 2 authors who screened records for inclusion were then asked whether spin was present in the abstract of the randomized trial. Spin in the title, abstract results, abstract conclusions, and selection of reported endpoints were considered.
Results:
Of the 651 PubMed citations retrieved by our search string, 194 RCTs with a clearly defined primary endpoint were identified. Of these 194 RCTs, 66 trials contained nonsignificant primary endpoints and were evaluated for spin. Of these trials, spin was identified in 18 of the 66 abstracts (27.3%).
Conclusions:
Spin was present in our sample of cardiology RCTs. Spin may influence clinical decision making by creating false impressions of the true validity of a drug or intervention.
In cardiology, the accurate reporting of results from randomized, controlled trials (RCTs) are essential to evidence-based clinical decision making. Biased reporting in RCTs has been shown to skew how physicians interpret findings; for example, the effect of biased reporting on physician interpretations of drug efficacy was examined in the SPIIN trial,
1 in which 300 oncologists were asked to read an abstract with nonsignificant results. The intervention group received a version of the abstract that contained “spin” (biased reporting in the form of misrepresented or distorted findings, or in this case, misleading conclusions), whereas the control group received an abstract without spin. Before reading the full text of the article, the interventional group concluded that the drug was more effective despite the nonsignificant results. Authors may use spin to draw misleading conclusions about their study as an attempt to persuade readers that their results were significant when, in fact, they were not.
Clinical trial abstracts play an important role in the medical literature. They provide a synopsis of the full trial report and are meant to guide the reader quickly through the background, methods, findings, and conclusions of the study. However, because of the brevity of most abstracts, authors may be forced to choose which results to include and which conclusions they wish to convey. Consequently, abstracts commonly have evidence of spin.
2 A previous study showed that internists frequently only read the abstract of a clinical trial, either to quickly browse the literature or screen out uninteresting reports.
3 If cardiologists emphasize abstracts in the same way, they may be susceptible to spin. Further, if cardiologists, also like internists, are more likely to read the full text of a trial with optimistic conclusions, they may be exposing themselves to additional spin, since the full text of RCTs has shown similar rates of misrepresented research findings.
2
For example, a 2011 evaluation of primary prevention trials of implantable-cardioverter defibrillators (ICD) found evidence of spin.
4 In these trials, the background information provided was often imbalanced, focusing more on the benefits and minimizing the harm. In interpreting the data from trials, the authors again emphasized the benefits and failed to adequately discuss the adverse events associated with the devices, resulting in misleading conclusions. Even if ICDs were as effective as the authors concluded, failing to balance the background and discussion is a rhetorical strategy of spin that likely affects how cardiologists understand the benefits and risks of ICDs.
The primary objective of this investigation was to assess the frequency and manifestations of spin in the abstracts of cardiology RCTs. The secondary objective was to determine whether the presence of a funding source is correlated with the presence of spin in RCT abstracts.