Spin in the abstracts of systematic reviews and metaanalyses focused on percutaneous coronary intervention

Context: “Spin” is a form of bias that involves highlighting study results in a way that presents the conclusions about benefit or efficacy beyond the scope of the data. Spin in the abstract of published studies has the potential to affect patient care, making investigations about its presence and prevalence important for readers.

Objectives: To evaluate the most severe types of spin in the abstracts of systematic reviews and metaanalyses focused on percutaneous coronary intervention.

Methods: Using a cross sectional study design, the authors searched MEDLINE and Embase with the terms “percutaneous coronary intervention,” “percutaneous coronary revascularization,” “PCI,” “systematic review,” “meta analysis,” and “meta-analysis.” To be considered for this study, the article must have (1) focused on PCI; (2) had either a systematic review or metaanalysis study design; (3) been conducted on human subjects; and (4) been available in English. Reviews were excluded if these criteria were not met. Each included article was assessed for the nine most severe types of spin as defined in a previously published article, as well as other study characteristics (type of intervention being compared, date the review was received, adherence of systematic review and/or meta-analysis to Preferred Reporting for Systematic Reviews or Metanalyses (PRISMA) guidelines, requirement of PRISMA guidelines by the publishing journal, the publishing journal’s five-year impact factor, and sources of funding).

Results: Our database search retrieved 7,038 records; 2,190 duplicates were removed. Initial title and abstract screening led to the exclusion of 4,367 records, and an additional 281 records were excluded during full text screening. An arbitrary limit of 200 articles was applied for this analysis; five additional articles were excluded for ineligible study design, so 195 were included in our final analysis. Spin was present in the abstracts of 43 studies from that pool (22.1%). Spin type 3—selective reporting of or overemphasis on efficacy outcomes or analysis favoring the beneficial effect of the experimental intervention—occurred most frequently (29; 14.8%). The presence of spin was not associated with any of the extracted study characteristics.

Conclusions: Our data showed that spin occurred in more than one in every five systematic reviews or metaanalyses of PCI. Spin has the potential to distort a reader’s ability to translate the true findings of a study; therefore, efforts are needed to prevent spin from appearing in article summaries.