Level and Prevalence of Spin in Published Cardiovascular
Randomized Clinical Trial Reports With Statistically Nonsignificant
A Systematic Review
Muhammad Shahzeb Khan, MD; Noman Lateef, MD; Tariq Jamal Siddiqi, MBBS; Karim Abdur Rehman, MD; Saed Alnaimat, MD; Safi U. Khan, MD; Haris Riaz, MD; M. Hassan Murad, MD; John Mandrola, MD; Rami Doukky, MD; Richard A. Krasuski, MD
IMPORTANCE Clinical researchers are obligated to present results objectively and accurately to
ensure readers are not misled. In studies in which primary end points are not statistically significant,
placing a spin, defined as the manipulation of language to potentially mislead readers from the likely
truth of the results, can distract the reader and lead to misinterpretation and misapplication of the
OBJECTIVE To determine the level and prevalence of spin in published reports of cardiovascular
randomized clinical trial (RCT) reports.
DATA SOURCE MEDLINE was searched from January 1, 2015, to December 31, 2017, using the
Cochrane highly sensitive search strategy.
STUDY SELECTION Inclusion criteria were parallel-group RCTs published from January 1, 2015, to
December 31, 2017 in 1 of 6 high-impact journals (New England Journal of Medicine, The Lancet,
JAMA, European Heart Journal, Circulation, and Journal of the American College of Cardiology) with
primary outcomes that were not statistically significant were included in the analysis.
DATA EXTRACTION AND SYNTHESIS Analysis began in August 2018. Data were extracted and
verified by 2 independent investigators using a standard collection form. In cases of disagreement
between the 2 investigators, a third investigators served as arbitrator.
MAIN OUTCOMES AND MEASURES The classifications of spin type, severity, and extent were
determined according to predefined criteria. Primary clinical outcomes were divided into safety of
treatment, efficacy of treatment, and both.
RESULTS Of 587 studies identified, 93 RCT reports (15.8%)met inclusion criteria. Spin was
identified in 53 abstracts (57%; 95%CI, 47%-67%) and 62 main texts of published articles (67%;
95%CI, 57%-75%). Ten reports (11%; 95%CI, 6%-19%) had spin in the title, 35 reports (38%; 95%CI,
28%-48%) had spin in the results section, and 50 reports (54%; 95%CI, 44%-64%) had spin in the
conclusions. Among the abstracts, spin was observed in 38 results sections (41%; 95%CI, 31%-51%)
and 45 conclusions sections (48%; 95%CI, 38%-58%).
CONCLUSIONS AND RELEVANCE This study suggests that in reports of cardiovascular RCTs with
statistically nonsignificant primary outcomes, investigators often manipulate the language of thereport to detract from the neutral primary outcomes. To best apply evidence to patient care,
consumers of cardiovascular research should be aware that peer review does not always preclude the
use of misleading language in scientific articles.
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