title: Authors seldom report the most patient-important outcomes and absolute effect measures in systematic review abstracts.
abstract: Explicit reporting of absolute measures is important to ensure treatment effects are correctly interpreted. We examined the extent to which authors report absolute effects for patient-important outcomes in abstracts of systematic review (SR).
  
  
  
  We searched OVID MEDLINE and Cochrane Database of Systematic Reviews to identify eligible SRs published in the year 2010. Citations were stratified into Cochrane and non-Cochrane reviews, with repeated random sampling in a 1:1 ratio. Paired reviewers screened articles and recorded abstract characteristics, including reporting of effect measures for the most patient-important outcomes of benefit and harm.
  
  
  
  We included 96 Cochrane and 94 non-Cochrane reviews. About 117 (77.5%) relative measures were reported in abstracts for outcomes of benefit, whereas only 34 (22.5%) absolute measures were reported. Similarly, for outcomes of harm, 41 (87.2%) relative measures were provided in abstracts, compared with only 6 (12.8%) absolute measures. Eighteen (9.5%) abstracts reported both absolute and relative measures for outcomes of benefit, whereas only two (1.1%) abstracts reported both measures for outcomes of harm. Results were similar between Cochrane and non-Cochrane reviews.
  
  
  
  SR abstracts seldom report measures of absolute effect. Journal editors should insist that authors report both relative and absolute effects for patient-important outcomes.
authors.affiliation: School of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada; Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Arnav
authors.initials: A
authors.lastname: Agarwal
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Institute of Health Policy, Management & Evaluation, University of Toronto, 4th Floor, 155 College St, Toronto, Ontario M5T 3M6, Canada; Systematic Overviews through advancing Research Technology (SORT), Child Health Evaluative Sciences, The Hospital for Sick Children Research Institute, University of Toronto, 686 Bay Street, Toronto, Ontario M5G 0A4, Canada; Department of Anesthesia & Pain Medicine, The Hospital for Sick Children, 555 University Ave., Toronto, Ontario M5G 1X8, Canada. Electronic address: bradley.johnston@sickkids.ca.
authors.forename: Bradley C
authors.initials: BC
authors.lastname: Johnston
authors.affiliation: Clinical Epidemiology and Public Health Department, Iberoamerican Cochrane Centre, Biomedical Research Institute Sant Pau (IIB Sant Pau), C/ Sant Antoni Maria Claret, 167, Pavelló 18, planta 0, 08025 Barcelona, Spain.
authors.forename: Robin W M
authors.initials: RW
authors.lastname: Vernooij
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Evidence-Based Dentistry Unit, Faculty of Dentistry, Universidad de Chile, Sergio Livingstone 943, Santiago, Chile.
authors.forename: Alonso
authors.initials: A
authors.lastname: Carrasco-Labra
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Evidence-Based Dentistry Unit, Faculty of Dentistry, Universidad de Chile, Sergio Livingstone 943, Santiago, Chile.
authors.forename: Romina
authors.initials: R
authors.lastname: Brignardello-Petersen
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Department of Medicine, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O Higgins 340, Santiago, Región Metropolitana, Chile.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Neumann
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Department of Internal Medicine, American University of Beirut Medical Center, P.O. Box: 11-0236, Riad-El-Solh, Beirut 1107 2020, Lebanon.
authors.forename: Elie A
authors.initials: EA
authors.lastname: Akl
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Chinese Evidence-based Medicine Center, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Chengdu 610041, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Basel Institute for Clinical Epidemiology and Biostatistics, Department of Clinical Research, University Hospital Basel, Spitalstrasse 12, Basel 4031, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Briel
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Michael G. DeGroote Institute for Pain Research and Care, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Department of Anesthesia, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Busse
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Department of Anesthesia, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Shanil
authors.initials: S
authors.lastname: Ebrahim
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Área de investigaciones, Facultad de Medicina, Universidad de La Sabana, Campus del Puente del Común Km, 7 Autopista Norte, Chía, Colombia.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Granados
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Iorio
authors.affiliation: Internal Medicine Residency Program, University of Illinois, Urbana-Champaign, 506 S. Mathews Ave., Urbana, IL 61801, USA.
authors.forename: Affan
authors.initials: A
authors.lastname: Irfan
authors.affiliation: Clinical Epidemiology and Public Health Department, Iberoamerican Cochrane Centre, Biomedical Research Institute Sant Pau (IIB Sant Pau), C/ Sant Antoni Maria Claret, 167, Pavelló 18, planta 0, 08025 Barcelona, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Martínez García
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Departments of Medicine and Biomedical & Health Informatics, University of Missouri-Kansas City, School of Medicine, M4-303, 2411 Holmes St, Kansas City, MO, USA.
authors.forename: Reem A
authors.initials: RA
authors.lastname: Mustafa
authors.affiliation: CCSS Permanent Medical Advisor, Health Care Development Division, IHCAI Foundation & Central America Cochrane, 1st Ave., 35th and 37th St, Number 3530, Barrio Escalante, San José, Costa Rica.
authors.forename: Anggie
authors.initials: A
authors.lastname: Ramirez-Morera
authors.affiliation: Clinical Epidemiology and Public Health Department, Iberoamerican Cochrane Centre, Biomedical Research Institute Sant Pau (IIB Sant Pau), C/ Sant Antoni Maria Claret, 167, Pavelló 18, planta 0, 08025 Barcelona, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Selva
authors.affiliation: Clinical Epidemiology and Public Health Department, Iberoamerican Cochrane Centre, Biomedical Research Institute Sant Pau (IIB Sant Pau), C/ Sant Antoni Maria Claret, 167, Pavelló 18, planta 0, 08025 Barcelona, Spain.
authors.forename: Ivan
authors.initials: I
authors.lastname: Solà
authors.affiliation: Clinical Epidemiology and Public Health Department, Iberoamerican Cochrane Centre, Biomedical Research Institute Sant Pau (IIB Sant Pau), C/ Sant Antoni Maria Claret, 167, Pavelló 18, planta 0, 08025 Barcelona, Spain.
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: Sanabrai
authors.affiliation: Departments of Urology and Public Health, Helsinki University Hospital and University of Helsinki, Haartmaninkatu 4, Helsinki 00029, Finland.
authors.forename: Kari A O
authors.initials: KA
authors.lastname: Tikkinen
authors.affiliation: Norwegian Knowledge Centre for the Health Services, P.O. Box 4404 Nydalen, Oslo 0403 Norway.
authors.forename: Per O
authors.initials: PO
authors.lastname: Vandvik
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Clinical Epidemiology and Public Health Department, Iberoamerican Cochrane Centre, Biomedical Research Institute Sant Pau (IIB Sant Pau), C/ Sant Antoni Maria Claret, 167, Pavelló 18, planta 0, 08025 Barcelona, Spain.
authors.forename: Oscar E
authors.initials: OE
authors.lastname: Zazueta
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Holger J
authors.initials: HJ
authors.lastname: Schunemann
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
authors.forename: Gordon H
authors.initials: GH
authors.lastname: Guyatt
authors.affiliation: Department of Clinical Epidemiology & Biostatistics, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada; Clinical Epidemiology and Public Health Department, Iberoamerican Cochrane Centre, Biomedical Research Institute Sant Pau (IIB Sant Pau), C/ Sant Antoni Maria Claret, 167, Pavelló 18, planta 0, 08025 Barcelona, Spain; CIBER of Epidemiology and Public Health (CIBERESP-IIB Sant Pau), Av. Monforte de Lemos, 3-5, Pabellón 11, Planta 0, Madrid 28029, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Alonso-Coello
mesh_terms: D000043:Abstracting and Indexing / Q000706:statistics & numerical data*; D001319:Authorship; D006801:Humans; D063868:Patient Outcome Assessment; D012107:Research Design; D058028:Research Report; D012196:Review Literature as Topic
keywords: Absolute measures; Abstract reporting; Cochrane reviews; Explicit reporting; Non-Cochrane reviews; Patient-important outcomes