title: Comparison of treatment effect estimates of non-vitamin K antagonist oral anticoagulants versus warfarin between observational studies using propensity score methods and randomized controlled trials.
abstract: Emerging observational studies using propensity score (PS) methods assessed real-world comparative effectiveness of non-vitamin K antagonist oral anticoagulants (NOACs) versus warfarin in patients with non-valvular atrial fibrillation (AF). We aimed to compare treatment effect estimates of NOACs between PS studies and randomized controlled trials (RCTs). Electronic databases and conference proceedings were searched systematically. Primary outcomes included stroke or systemic embolism (SE) and major bleeding. A random-effects meta-analysis was performed to synthesize the data by pooling the PS- and RCT-derived hazard ratios (HRs) separately. The ratio of HRs (RHR) from the ratio of PS-derived HRs relative to RCT-derived HRs was used to determine whether there was a difference between estimates from PS studies and RCTs. There were 10 PS studies and 5 RCTs included for analysis. No significant difference of treatment effect estimates between the PS studies and RCTs was observed: RHR 1.11, 95 % CI 0.98-1.23 for stroke or SE; RHR 1.07, 95 % CI 0.87-1.34 for major bleeding. A significant association between NOACs and risk of stroke or SE was observed: HR 0.88, 95 % CI 0.83-0.94 for the PS studies; HR 0.79, 95 % CI 0.72-0.87 for the RCTs. However, no relationship between NOACs and risk of major bleeding was found: HR 0.91, 95 % CI 0.79-1.05 for the PS studies; HR 0.85, 95 % CI 0.73-1.00 for the RCTs. In this study, treatment effect estimates of NOACs versus warfarin in patients with non-valvular AF from PS studies are found to be in agreement with those from RCTs.
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada. lig28@mcmaster.ca.|St. Joseph's Healthcare Hamilton, 50 Charlton Avenue East, Hamilton, ON, L8N 4A6, Canada. lig28@mcmaster.ca.
authors.forename: Guowei
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.|St. Joseph's Healthcare Hamilton, 50 Charlton Avenue East, Hamilton, ON, L8N 4A6, Canada.|Department of Medicine, McMaster University, Hamilton, ON, Canada.
authors.forename: Anne
authors.initials: A
authors.lastname: Holbrook
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Epidemiology, School of Public Health, Soochow University, Suzhou, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.|St. Joseph's Healthcare Hamilton, 50 Charlton Avenue East, Hamilton, ON, L8N 4A6, Canada.|Department of Medicine, McMaster University, Hamilton, ON, Canada.
authors.forename: Mitchell A H
authors.initials: MA
authors.lastname: Levine
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.|St. Joseph's Healthcare Hamilton, 50 Charlton Avenue East, Hamilton, ON, L8N 4A6, Canada.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Mbuagbaw
authors.affiliation: Department of Pharmacotherapy, University of Utah, Salt Lake City, UT, USA.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Witt
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.|St. Joseph's Healthcare Hamilton, 50 Charlton Avenue East, Hamilton, ON, L8N 4A6, Canada.|Department of Medicine, McMaster University, Hamilton, ON, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Crowther
authors.affiliation: Department of Medicine, McMaster University, Hamilton, ON, Canada.|Population Health Research Institute, McMaster University, Hamilton, ON, Canada.
authors.forename: Stuart
authors.initials: S
authors.lastname: Connolly
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.
authors.forename: Chatree
authors.initials: C
authors.lastname: Chai-Adisaksopha
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, China.
authors.forename: Zhongxiao
authors.initials: Z
authors.lastname: Wan
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.|St. Joseph's Healthcare Hamilton, 50 Charlton Avenue East, Hamilton, ON, L8N 4A6, Canada.
authors.forename: Ji
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada. thabanl@mcmaster.ca.|St. Joseph's Healthcare Hamilton, 50 Charlton Avenue East, Hamilton, ON, L8N 4A6, Canada. thabanl@mcmaster.ca.
authors.forename: Lehana
authors.initials: L
authors.lastname: Thabane
mesh_terms: D000284:Administration, Oral; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000517:prevention & control*; D006801:Humans; D057216:Propensity Score; D016032:Randomized Controlled Trials as Topic; D020521:Stroke / Q000517:prevention & control*; D016896:Treatment Outcome; D014812:Vitamin K / Q000037:antagonists & inhibitors; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D014812:Vitamin K; D014859:Warfarin
keywords: Anticoagulant; Atrial fibrillation; Propensity score method; Stroke; Warfarin