title: Quality and clarity in systematic review abstracts: an empirical study.
abstract: BACKGROUND
  Systematic review (SR) abstracts are important for disseminating evidence syntheses to inform medical decision making. We assess reporting quality in SR abstracts using PRISMA for Abstracts (PRISMA-A), Cochrane Handbook, and Agency for Healthcare Research & Quality guidance.
  
  
  METHODS
  We evaluated a random sample of 200 SR abstracts (from 2014) comparing interventions in the general medical literature. We assessed adherence to PRISMA-A criteria, problematic wording in conclusions, and whether "positive" studies described clinical significance.
  
  
  RESULTS
  On average, abstracts reported 60% of PRISMA-A checklist items (mean 8.9 ± 1.7, range 4 to 12). Eighty percent of meta-analyses reported quantitative measures with a confidence interval. Only 49% described effects in terms meaningful to patients and clinicians (e.g., absolute measures), and only 43% mentioned strengths/limitations of the evidence base. Average abstract word count was 274 (SD 89). Word count explained only 13% of score variability. PRISMA-A scores did not differ between Cochrane and non-Cochrane abstracts (mean difference 0.08, 95% confidence interval -1.16 to 1.00). Of 275 primary outcomes, 48% were statistically significant, 32% were not statistically significant, and 19% did not report significance or results. Only one abstract described clinical significance for positive findings. For "negative" outcomes, we identified problematic simple restatements (20%), vague "no evidence of effect" wording (9%), and wishful wording (8%).
  
  
  CONCLUSIONS
  Improved SR abstract reporting is needed, particularly reporting of quantitative measures (for meta-analysis), easily interpretable units, strengths/limitations of evidence, clinical significance, and clarifying whether negative results reflect true equivalence between treatments. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: ECRI Institute, Health Technology Information Service and Evidence-based Practice Center, Plymouth Meeting, PA, USA.|Corporal Michael J. Crescenz Veterans Affairs Medical Center (VAMC), Philadelphia, PA, USA.
authors.forename: Amy Y
authors.initials: AY
authors.lastname: Tsou
authors.affiliation: ECRI Institute, Health Technology Information Service and Evidence-based Practice Center, Plymouth Meeting, PA, USA.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Treadwell
mesh_terms: D000043:Abstracting and Indexing / Q000592:standards; D016206:Databases, Bibliographic; D003657:Decision Making; D036262:Empirical Research; D010506:Periodicals as Topic / Q000592:standards; D011643:Publishing / Q000592:standards; D011786:Quality Control; D012107:Research Design; D000078202:Systematic Reviews as Topic; D014481:United States; D016270:United States Agency for Healthcare Research and Quality
keywords: PRISMA; clinical significance; minimally important difference; reporting quality; systematic review abstracts